Method, apparatus, device and network system for adding secondary serving cell

ABSTRACT

The present invention provides a method for adding a secondary serving cell, an apparatus, a device, and a network system. The method includes: communicating, with each other to acquire a unified serial number of a random access preamble code, a unified serial number of a PRACH mask code, and a unified cell radio network temporary identifier of a terminal; scrambling the serial number of the random access preamble code and the serial number of the PRACH mask code, and then sending the serial number of the random access preamble code and the serial number of the PRACH mask code to the terminal,; and determining, a time advance command TAC according to a random access request message that carries the random access preamble code, and sending the TAC to the terminal.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/898,523, filed on Feb. 17, 2018, which is a continuation of U.S.application Ser. No. 14/611,428, filed on Feb. 2, 2015, which is acontinuation of International Application No. PCT/CN2012/079421, filedon Jul. 31, 2012. All of the aforementioned patent applications arehereby incorporated by reference in their entireties.

TECHNICAL FIELD

The present invention relates to wireless communications technologies,and in particular, to a method for adding a secondary serving cell, anapparatus, a device, and a network system.

BACKGROUND

A type of network deployment has been introduced to a next generationwireless network, and in this type of network deployment, one basestation has two cells of different frequencies, and a terminal maymaintain connection to the two cells of different frequencies of onebase station simultaneously. Of the cells that maintain connection toone terminal, one is a primary serving cell and the other is a secondaryserving cell. FIG. 1 is a schematic signaling diagram of a networksystem. As shown in FIG. 1, communication between a terminal and a basestation may be divided into the following several steps: first, the basestation sends a random access resource allocation message to theterminal over a primary serving cell, where the message includes aserial number of a random access preamble code and a serial number of aphysical random access channel (Physical Random Access Channel,hereinafter referred to as PRACH) mask code, and the message uses a cellradio network temporary identifier (Cell Radio Network TemporaryIdentifier, hereinafter referred to as C-RNTI) to scramble the randomaccess resource allocation message; second, after using the C-RNTI todescramble the received random access resource allocation message, theterminal sends a random access request message to the base station overa secondary serving cell according to the random access resourceallocation message received by the terminal, where the random accessrequest message includes a random access preamble code; third, the basestation sends a random access response message to the terminal over theprimary serving cell according to the received random access requestmessage, where the random access response message includes a timeadvance command TAC (Time Advance Command, hereinafter referred to asTAC); and finally, the terminal adjusts, according to the random accessresponse message sent by the base station, time advance (Time Advance,hereinafter referred to as TA) of the terminal on the secondary servingcell.

In actual network deployment, the primary serving cell and the secondaryserving cell may also belong to different base stations. A base stationto which the primary serving cell belongs is referred to as a primarybase station, and a base station to which the secondary serving cellbelongs is referred to as a secondary base station. FIG. 2 is aschematic signaling diagram of a network system. As shown in FIG. 2, anoverall communication process of the system is as follows: first, aprimary base station sends a random access resource allocation messageto a terminal; second, the terminal sends a random access requestmessage to a secondary base station; and finally, the primary basestation sends a random access response message to the terminal.

In a process of implementing the present invention, the finds thatnormal communication cannot be performed when the primary serving celland the secondary serving cell are connected but a delay over theconnection is relatively long and a capacity is relatively small,wherein the capacity is the maximum data transfer rate of backhaul linkbetween primary cell and secondary cell, as specifically shown in FIG.2. First, the secondary base station does not know content of a randomaccess resource allocation message sent by the primary base station tothe terminal is, and as a result, a random access request message cannotbe correctly received. Second, the primary base station does not knowwhen the secondary base station receives the random access requestmessage sent by the terminal and cannot determine when to send a randomaccess response message to the terminal. Third, because the primary basestation does not know content of the random access request message sentby the terminal to the secondary base station, the primary base stationcannot correctly send the random access response message to theterminal.

SUMMARY

Embodiments of the present invention provide a method for adding asecondary serving cell, an apparatus, a device, and a network system.According to the technical solutions provided in the embodiments of thepresent invention, a primary serving cell and a secondary serving cellcan still work properly when the primary serving cell and the secondaryserving cell belong to different base stations, or a delay over theconnection between the primary serving cell and the secondary servingcell is relatively long and a capacity is relatively small.

An embodiment of the present invention provides a method for adding asecondary serving cell, and the method includes:

receiving, by a terminal, a random access resource allocation messagesent by a primary base station, where the random access resourceallocation message includes a serial number of a random access preamblecode and a serial number of a physical random access channel mask code;

sending, by the terminal, a random access request message to a secondarybase station by using a sending resource that is determined according tothe serial number of the physical random access channel mask code, wherethe random access request message includes the random access preamblecode that is determined according to the serial number of the randomaccess preamble code;

receiving, by the terminal, a random access response message sent by theprimary base station, where the random access response message includesa time advance command TAC that is sent by the secondary base station tothe primary base station and is determined by the secondary base stationaccording to the random access request message; and

adjusting, by the terminal according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

Further, before the receiving, by a terminal, a random access resourceallocation message sent by a primary base station, the terminal furtherreceives a cell radio network temporary identifier sent by the primarybase station; and after the receiving, by a terminal, a random accessresource allocation message sent by a primary base station, the terminaluses the cell radio network temporary identifier to descramble therandom access resource allocation message.

An embodiment of the present invention provides a method for adding asecondary serving cell, and the method includes:

sending, by a primary base station, a random access resource allocationmessage and a secondary serving cell addition request message to aterminal and a secondary base station, respectively, where both therandom access resource allocation message and the secondary serving celladdition request message include a serial number of a random accesspreamble code and a serial number of a physical random access channelmask code;

receiving, by the primary base station, a time advance command TACtransmission message sent by the secondary base station, where the TACtransmission message is sent to the primary base station after thesecondary base station receives a random access request message that issent by the terminal and carries the random access preamble codeobtained according to the serial number of the random access preamblecode; and the TAC transmission message includes a TAC obtained by thesecondary base station according to the random access request message;and

sending, by the primary base station to the terminal, a random accessresponse message that carries the TAC, so that the terminal adjusts,according to the TAC, time advance TA of the terminal on a secondaryserving cell corresponding to the secondary base station.

Further, before the sending, by a primary base station, a random accessresource allocation message to a terminal, the primary base stationfurther sends a cell radio network temporary identifier of the terminalto the terminal; and the primary base station uses the cell radionetwork temporary identifier of the terminal to scramble the randomaccess resource allocation message, and then sends the random accessresource allocation message to the terminal.

Further, the time advance command TAC transmission message furtherincludes a first time at which the secondary base station receives therandom access request message; and

correspondingly, the primary base station determines, according to thefirst time, a second time for sending the random access responsemessage.

An embodiment of the present invention provides a method for adding asecondary serving cell, and the method includes:

receiving, by a secondary base station, a secondary serving celladdition request message sent by a primary base station, where thesecondary serving cell addition request message includes a serial numberof a random access preamble code and a serial number of a physicalrandom access channel mask code;

receiving, by the secondary base station according to the secondaryserving cell addition request message, a random access request messagethat is sent by a terminal and carries the random access preamble codeobtained according to the serial number of the random access preamblecode; and

obtaining, by the secondary base station, a time advance command TACaccording to the random access request message, and sending, to theprimary base station, a time advance command TAC transmission messagethat carries the TAC, so that the primary base station sends, to theterminal, a random access response message that carries the TAC so thatthe terminal adjusts, according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

Further, the time advance command TAC transmission message furtherincludes a first time at which the secondary base station receives therandom access request message, so that the primary base stationdetermines, according to the first time, a second time for sending therandom access response message.

An embodiment of the present invention provides a terminal, and theterminal includes:

a first unit, configured to receive a random access resource allocationmessage sent by a primary base station, where the random access resourceallocation message includes a serial number of a random access preamblecode and a serial number of a physical random access channel mask code;

a second unit, configured to send a random access request message to asecondary base station by using a sending resource that is determinedaccording to the serial number of the physical random access channelmask code, where the random access request message includes the randomaccess preamble code that is determined according to the serial numberof the random access preamble code;

a third unit, configured to receive a random access response messagesent by the primary base station, where the random access responsemessage includes a time advance command TAC that is sent by thesecondary base station to the primary base station and is determined bythe secondary base station according to the random access requestmessage; and

a fourth unit, configured to adjust, according to the TAC, time advanceTA of the terminal on a secondary serving cell corresponding to thesecondary base station.

An embodiment of the present invention provides a primary base station,and the primary base station includes:

a fifth unit, configured to send a random access resource allocationmessage and a secondary serving cell addition request message to aterminal and a secondary base station, respectively, where both therandom access resource allocation message and the secondary serving celladdition request message include a serial number of a random accesspreamble code and a serial number of a physical random access channelmask code;

a sixth unit, configured to receive a time advance command TACtransmission message sent by the secondary base station, where the TACtransmission message is sent to the primary base station after thesecondary base station receives a random access request message that issent by the terminal and carries the random access preamble codeobtained according to the serial number of the random access preamblecode; and the TAC transmission message includes a TAC obtained by thesecondary base station according to the random access request message;and

a seventh unit, configured to send, to the terminal, a random accessresponse message that carries the TAC, so that the terminal adjusts,according to the TAC, time advance TA of the terminal on a secondaryserving cell corresponding to the secondary base station.

Further, the time advance command TAC transmission message furtherincludes a first time at which the secondary base station receives therandom access request message; and

correspondingly, the seventh unit is further configured to determine,according to the first time, a second time for sending the random accessresponse message.

An embodiment of the present invention provides a secondary basestation, and the secondary base station includes:

an eighth unit, configured to receive a secondary serving cell additionrequest message sent by a primary base station, where the secondaryserving cell addition request message includes a serial number of arandom access preamble code and a serial number of a physical randomaccess channel mask code;

a ninth unit, configured to receive, according to the secondary servingcell addition request message, a random access request message that issent by a terminal and carries the random access preamble code; and

a tenth unit, configured to obtain a time advance command TAC accordingto the random access request message, and send, to the primary basestation, a time advance command TAC transmission message that carriesthe TAC, so that the primary base station sends, to the terminal, arandom access response message that carries the TAC so that the terminaladjusts, according to the TAC, time advance TA of the terminal on asecondary serving cell corresponding to the secondary base station.

Further, the time advance command TAC transmission message furtherincludes a first time at which the secondary base station receives therandom access request message, so that the primary base stationdetermines, according to the first time, a second time for sending therandom access response message.

A terminal device, including:

a first receiving unit, configured to receive a random access resourceallocation message sent by a primary base station, where the randomaccess resource allocation message includes a serial number of a randomaccess preamble code and a serial number of a physical random accesschannel mask code;

a first sending unit, configured to send a random access request messageto a secondary base station by using a sending resource that isdetermined according to the serial number of the physical random accesschannel mask code, where the random access request message includes therandom access preamble code that is determined according to the serialnumber of the random access preamble code;

a second receiving unit, configured to receive a random access responsemessage sent by the primary base station, where the random accessresponse message includes a time advance command TAC that is sent by thesecondary base station to the primary base station and is determined bythe secondary base station according to the random access requestmessage; and

a first processing unit, configured to adjust, according to the TAC,time advance TA of the terminal on a secondary serving cellcorresponding to the secondary base station.

A primary base station, including:

a second sending unit, configured to send a random access resourceallocation message and a secondary serving cell addition request messageto a terminal and a secondary base station, respectively, where both therandom access resource allocation message and the secondary serving celladdition request message include a serial number of a random accesspreamble code and a serial number of a physical random access channelmask code;

a third receiving unit, configured to receive a time advance command TACtransmission message sent by the secondary base station, where the TACtransmission message is sent to the primary base station after thesecondary base station receives a random access request message that issent by the terminal and carries the random access preamble codeobtained according to the serial number of the random access preamblecode; and the TAC transmission message includes a TAC obtained by thesecondary base station according to the random access request message;and

a third sending unit, configured to send, to the terminal, a randomaccess response message that carries the TAC, so that the terminaladjusts, according to the TAC, time advance TA of the terminal on asecondary serving cell corresponding to the secondary base station.

According to the foregoing primary base station device, the time advancecommand TAC transmission message further includes a first time at whichthe secondary base station receives the random access request message;and

correspondingly, the third sending unit is further configured todetermine, according to the first time, a second time for sending therandom access response message.

A secondary base station device, including:

a fourth receiving unit, configured to receive a secondary serving celladdition request message sent by a primary base station, where thesecondary serving cell addition request message includes a serial numberof a random access preamble code and a serial number of a physicalrandom access channel mask code;

a fifth receiving unit, configured to receive, according to thesecondary serving cell addition request message, a random access requestmessage that is sent by a terminal and carries the random accesspreamble code; and

a fourth sending unit, configured to obtain a time advance command TACaccording to the random access request message, and send, to the primarybase station, a time advance command TAC transmission message thatcarries the TAC, so that the primary base station sends, to theterminal, a random access response message that carries the TAC so thatthe terminal adjusts, according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

According to the foregoing secondary base station device, the timeadvance command TAC transmission message further includes a first timeat which the secondary base station receives the random access requestmessage, so that the primary base station determines, according to thefirst time, a second time for sending the random access responsemessage.

An embodiment of the present invention provides a network system, andthe network system includes the terminal, the primary base station, andthe secondary base station provided in the foregoing embodiments.

An embodiment of the present invention provides a network system, andthe network system includes the terminal device, the primary basestation device, and the secondary base station device provided in theforegoing embodiments.

An embodiment of the present invention yet provides a method for addinga secondary serving cell, and the method includes:

receiving, by a terminal, a notification message sent by a primary basestation, where the notification message includes a serial number of arandom access preamble code and a serial number of a physical randomaccess channel mask code;

sending, by the terminal, a random access request message to a secondarybase station by using a sending resource that is determined according tothe serial number of the physical random access channel mask code, wherethe random access request message includes the random access preamblecode that is determined according to the serial number of the randomaccess preamble code;

receiving, by the terminal, a random access response message sent by thesecondary base station, where the random access response messageincludes a time advance command TAC that is determined by the secondarybase station according to the random access request message; and

adjusting, by the terminal according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

Further, the notification message is a reconfiguration message or arandom access resource allocation message; when the notification messageis a random access resource allocation message, the terminal furtherreceives a reconfiguration message sent by the primary base station; andcorrespondingly, the reconfiguration message further includes a randomaccess response window size, of the secondary serving cell, that is usedby the terminal to receive the random access response message.

Further, before the receiving, by a terminal, a notification messagesent by a primary base station, the terminal further receives a cellradio network temporary identifier sent by the primary base station; andafter the receiving, by a terminal, a notification message sent by aprimary base station, the terminal uses the cell radio network temporaryidentifier of the terminal to perform descrambling, to obtain the serialnumber of the random access preamble code and the serial number of thephysical random access channel mask code.

An embodiment of the present invention yet provides a method for addinga secondary serving cell, and the method includes:

receiving, by a secondary base station, a secondary serving celladdition request message sent by a primary base station, where thesecondary serving cell addition request message includes a serial numberof a random access preamble code and a serial number of a physicalrandom access channel mask code;

receiving, by the secondary base station according to the secondaryserving cell addition request message, a random access request messagethat is sent by a terminal and carries the random access preamble codeobtained according to the serial number of the random access preamblecode; and

obtaining, by the secondary base station, a time advance command TACaccording to the random access request message, and sending, to theterminal, a random access response message that carries the TAC, so thatthe terminal adjusts, according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

An embodiment of the present invention still provides a method foradding a secondary serving cell, and the method includes:

sending, by a secondary base station, a secondary serving cell additionresponse message to a primary base station, where the secondary servingcell addition response message includes a serial number of a randomaccess preamble code and a serial number of a physical random accesschannel mask code;

receiving, by the secondary base station, a random access requestmessage that is sent by a terminal and carries the random accesspreamble code obtained according to the serial number of the randomaccess preamble code; and

obtaining, by the secondary base station, a time advance command TACaccording to the random access request message, and sending, to theterminal, a random access response message that carries the TAC, so thatthe terminal adjusts, according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

Further, the secondary serving cell addition response message furtherincludes a random access response window size, of the secondary servingcell, that is used by the terminal to receive the random access responsemessage.

An embodiment of the present invention yet provides a terminal, and theterminal includes:

an eleventh unit, configured to receive a notification message sent by aprimary base station, where the notification message includes a serialnumber of a random access preamble code and a serial number of aphysical random access channel mask code;

a twelfth unit, configured to send a random access request message to asecondary base station by using a sending resource that is determinedaccording to the serial number of the physical random access channelmask code, where the random access request message includes the randomaccess preamble code that is determined according to the serial numberof the random access preamble code;

a thirteenth unit, configured to receive a random access responsemessage sent by the secondary base station, where the random accessresponse message includes a time advance command TAC that is determinedby the secondary base station according to the random access requestmessage; and

a fourteenth unit, configured to adjust, according to the TAC, timeadvance TA of the terminal on a secondary serving cell corresponding tothe secondary base station.

An embodiment of the present invention yet provides a secondary basestation, and the secondary base station includes:

a fifteenth unit, configured to receive a secondary serving celladdition request message sent by a primary base station, where thesecondary serving cell addition request message includes a serial numberof a random access preamble code and a serial number of a physicalrandom access channel mask code;

a sixteenth unit, configured to receive, according to the secondaryserving cell addition request message, a random access request messagethat is sent by a terminal and carries the random access preamble codeobtained according to the serial number of the random access preamblecode; and

a seventeenth unit, configured to obtain a time advance command TACaccording to the random access request message, and send, to theterminal, a random access response message that carries the TAC, so thatthe terminal adjusts, according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

An embodiment of the present invention still provides a secondary basestation, and the secondary base station includes:

an eighteenth unit, configured to send a secondary serving cell additionresponse message to a primary base station, where the secondary servingcell addition response message includes a serial number of a randomaccess preamble code and a serial number of a physical random accesschannel mask code;

a nineteenth unit, configured to receive a random access request messagethat is sent by a terminal and carries the random access preamble codeobtained according to the serial number of the random access preamblecode; and

a twentieth unit, configured to obtain a time advance command TACaccording to the random access request message, and send, to theterminal, a random access response message that carries the TAC, so thatthe terminal adjusts, according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

Further, the secondary serving cell addition response message furtherincludes a random access response window size, of the secondary servingcell, that is used by the terminal to receive the random access responsemessage.

A terminal device, including:

a sixth receiving unit, configured to receive a notification messagesent by a primary base station, where the notification message includesa serial number of a random access preamble code and a serial number ofa physical random access channel mask code;

a fifth sending unit, configured to send a random access request messageto a secondary base station by using a sending resource that isdetermined according to the serial number of the physical random accesschannel mask code, where the random access request message includes therandom access preamble code that is determined according to the serialnumber of the random access preamble code;

a seventh receiving unit, configured to receive a random access responsemessage sent by the secondary base station, where the random accessresponse message includes a time advance command TAC that is determinedby the secondary base station according to the random access requestmessage; and

a second processing unit, configured to adjust, according to the TAC,time advance TA of the terminal on a secondary serving cellcorresponding to the secondary base station.

According to the foregoing terminal device, the notification message isa reconfiguration message or a random access resource allocationmessage; when the notification message is a random access resourceallocation message, a terminal further receives a reconfigurationmessage sent by the primary base station; and correspondingly, thereconfiguration message further includes a random access response windowsize, of the secondary serving cell, that is used by the terminal toreceive the random access response message.

According to the foregoing terminal device, before a terminal receivesthe notification message sent by the primary base station, the terminalfurther receives a cell radio network temporary identifier sent by theprimary base station; and after a terminal receives the notificationmessage sent by the primary base station, the terminal uses the cellradio network temporary identifier to perform descrambling, to obtainthe serial number of the random access preamble code and the serialnumber of the physical random access channel mask code.

A secondary base station device, including:

an eighth receiving unit, configured to receive a secondary serving celladdition request message sent by a primary base station, where thesecondary serving cell addition request message includes a serial numberof a random access preamble code and a serial number of a physicalrandom access channel mask code;

a ninth receiving unit, configured to receive, according to thesecondary serving cell addition request message, a random access requestmessage that is sent by a terminal and carries the random accesspreamble code obtained according to the serial number of the randomaccess preamble code; and

a sixth sending unit, configured to obtain a time advance command TACaccording to the random access request message, and send, to theterminal, a random access response message that carries the TAC, so thatthe terminal adjusts, according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

A secondary base station device, including:

a seventh sending unit, configured to send a secondary serving celladdition response message to a primary base station, where the secondaryserving cell addition response message includes a serial number of arandom access preamble code and a serial number of a physical randomaccess channel mask code;

a tenth receiving unit, configured to receive a random access requestmessage that is sent by a terminal and carries the random accesspreamble code obtained according to the serial number of the randomaccess preamble code; and

an eighth sending unit, configured to obtain a time advance command TACaccording to the random access request message, and send, to theterminal, a random access response message that carries the TAC, so thatthe terminal adjusts, according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

According to the foregoing secondary base station device, the secondaryserving cell addition response message further includes a random accessresponse window size, of the secondary serving cell, that is used by theterminal to receive the random access response message.

An embodiment of the present invention yet provides a network system,and the network system includes the terminal, the secondary basestation, and the primary base station provided in the foregoingembodiments.

An embodiment of the present invention yet provides a network system,and the network system includes the terminal device, the secondary basestation device, and the primary base station device provided in theforegoing embodiments.

An embodiment of the present invention still provides a method foradding a secondary serving cell, and the method includes:

receiving, by a terminal, a random access resource allocation messagesent by a secondary base station, where the random access resourceallocation message includes a serial number of a random access preamblecode and a serial number of a physical random access channel mask code;

sending, by the terminal, a random access request message to a secondarybase station by using a sending resource that is determined according tothe serial number of the physical random access channel mask code, wherethe random access request message includes the random access preamblecode that is determined according to the serial number of the randomaccess preamble code;

receiving, by the terminal, a random access response message sent by thesecondary base station, where the random access response messageincludes a time advance command TAC that is determined by the secondarybase station according to the random access request message; and

adjusting, by the terminal according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

Further, the method further includes: receiving, by the terminal, areconfiguration message sent by a primary base station, where thereconfiguration message includes a random access response window size,of the secondary serving cell, that is used by the terminal to receivethe random access response message, or the reconfiguration messageincludes the response window size and activation time, and the terminaldetermines, according to the activation time, a time for receiving therandom access resource allocation message.

An embodiment of the present invention yet still provides a method foradding a secondary serving cell, and the method includes:

sending, by a secondary base station, a random access resourceallocation message to a terminal after receiving a secondary servingcell addition request message sent by a primary base station, where thesecondary serving cell addition request message includes a cell radionetwork temporary identifier of the terminal and the random accessresource allocation message includes a serial number of a random accesspreamble code and a serial number of a physical random access channelmask code;

receiving, by the secondary base station, a random access requestmessage that is sent by the terminal and carries the random accesspreamble code obtained according to the serial number of the randomaccess preamble code; and

obtaining, by the secondary base station, a time advance command TACaccording to the random access request message, and sending, to theterminal, a random access response message that carries the TAC, so thatthe terminal adjusts, according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

Further, the secondary serving cell addition request message furtherincludes activation time, and the secondary base station determines,according to the activation time, a time for sending the random accessresource allocation message.

An embodiment of the present invention still further provides a methodfor adding a secondary serving cell, and the method includes:

after a secondary base station sends a secondary serving cell additionresponse message to a primary base station, sending a random accessresource allocation message to a terminal, where the secondary servingcell addition response message includes a cell radio network temporaryidentifier of the terminal and the random access resource allocationmessage includes a serial number of a random access preamble code and aserial number of a physical random access channel mask code;

receiving, by the secondary base station, a random access requestmessage that is sent by the terminal and carries the random accesspreamble code obtained according to the serial number of the randomaccess preamble code; and

obtaining, by the secondary base station, a time advance command TACaccording to the random access request message, and sending, to theterminal, a random access response message that carries the TAC, so thatthe terminal adjusts, according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

Further, the secondary serving cell addition response message furtherincludes activation time, and the secondary base station determines,according to the activation time, a time for sending the random accessresource allocation message.

An embodiment of the present invention still provides a terminal, andthe terminal includes:

a twenty-first unit, configured to receive a random access resourceallocation message sent by a secondary base station, where the randomaccess resource allocation message includes a serial number of a randomaccess preamble code and a serial number of a physical random accesschannel mask code;

a twenty-second unit, configured to send a random access request messageto a secondary base station by using a sending resource that isdetermined according to the serial number of the physical random accesschannel mask code, where the random access request message includes therandom access preamble code that is determined according to the serialnumber of the random access preamble code;

a twenty-third unit, configured to receive a random access responsemessage sent by the secondary base station, where the random accessresponse message includes a time advance command TAC that is determinedby the secondary base station according to the random access requestmessage; and

a twenty-fourth unit, configured to adjust, according to the TAC, timeadvance TA of the terminal on a secondary serving cell corresponding tothe secondary base station.

Further, according to the foregoing terminal, the twenty-first unit isfurther configured to receive a reconfiguration message sent by aprimary base station, where the reconfiguration message includes arandom access response window size, of the secondary serving cell, thatis used by the terminal to receive the random access response message,or the reconfiguration message includes the response window size andactivation time, and the terminal determines, according to theactivation time, a time for receiving the random access resourceallocation message.

An embodiment of the present invention yet still provides a secondarybase station, and the secondary base station includes:

a twenty-fifth unit, configured to, after receiving a secondary servingcell addition request message sent by a primary base station, send arandom access resource allocation message to a terminal, where thesecondary serving cell addition request message includes a cell radionetwork temporary identifier of the terminal and the random accessresource allocation message includes a serial number of a random accesspreamble code and a serial number of a physical random access channelmask code;

a twenty-sixth unit, configured to receive a random access requestmessage that is sent by the terminal and carries the random accesspreamble code obtained according to the serial number of the randomaccess preamble code; and

a twenty-seventh unit, configured to obtain a time advance command TACaccording to the random access request message, and send, to theterminal, a random access response message that carries the TAC, so thatthe terminal adjusts, according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

Further, the secondary serving cell addition request message furtherincludes activation time, and the secondary base station determines,according to the activation time, a time for sending the random accessresource allocation message.

An embodiment of the present invention still further provides asecondary base station, and the secondary base station includes:

a twenty-eighth unit, configured to, after sending a secondary servingcell addition response message to a primary base station, send a randomaccess resource allocation message to a terminal, where the secondaryserving cell addition response message includes a cell radio networktemporary identifier of the terminal and the random access resourceallocation message includes a serial number of a random access preamblecode and a serial number of a physical random access channel mask code;

a twenty-ninth unit, configured to receive a random access requestmessage that is sent by the terminal and carries the random accesspreamble code obtained according to the serial number of the randomaccess preamble code; and

a thirtieth unit, configured to obtain a time advance command TACaccording to the random access request message, and send, to theterminal, a random access response message that carries the TAC, so thatthe terminal adjusts, according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

Further, the secondary serving cell addition response message furtherincludes activation time, and the secondary base station determines,according to the activation time, a time for sending the random accessresource allocation message.

A terminal device, including:

an eleventh receiving unit, configured to receive a random accessresource allocation message sent by a secondary base station, where therandom access resource allocation message includes a serial number of arandom access preamble code and a serial number of a physical randomaccess channel mask code;

a ninth sending unit, configured to send a random access request messageto a secondary base station by using a sending resource that isdetermined according to the serial number of the physical random accesschannel mask code, where the random access request message includes therandom access preamble code that is determined according to the serialnumber of the random access preamble code;

a twelfth receiving unit, configured to receive a random access responsemessage sent by the secondary base station, where the random accessresponse message includes a time advance command TAC that is determinedby the secondary base station according to the random access requestmessage; and

a third processing unit, configured to adjust, according to the TAC,time advance TA of the terminal on a secondary serving cellcorresponding to the secondary base station.

According to the foregoing terminal device, the eleventh receiving unitis further configured to receive a reconfiguration message sent by aprimary base station, where the reconfiguration message includes arandom access response window size, of the secondary serving cell, thatis used by a terminal to receive the random access response message, orthe reconfiguration message includes the response window size andactivation time, and the terminal determines, according to theactivation time, a time for receiving the random access resourceallocation message.

According to the foregoing terminal device, the eleventh receiving unitis further configured to, before receiving the random access resourceallocation message, further receive a cell radio network temporaryidentifier of a terminal sent by a primary base station, where theterminal uses the cell radio network temporary identifier to descramblethe received random access resource allocation message.

A secondary base station device, including:

a thirteenth receiving unit, configured to receive a secondary servingcell addition request message sent by a primary base station; a tenthsending unit, configured to, after receiving the secondary serving celladdition request message sent by the primary base station, send a randomaccess resource allocation message to a terminal, where the secondaryserving cell addition request message includes a cell radio networktemporary identifier of the terminal and the random access resourceallocation message includes a serial number of a random access preamblecode and a serial number of a physical random access channel mask code;

a fourteenth receiving unit, configured to receive a random accessrequest message that is sent by the terminal and carries the randomaccess preamble code obtained according to the serial number of therandom access preamble code; and

an eleventh sending unit, configured to obtain a time advance commandTAC according to the random access request message, and send, to theterminal, a random access response message that carries the TAC, so thatthe terminal adjusts, according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

According to the foregoing secondary base station device, the secondaryserving cell addition request message further includes activation time,and the secondary base station determines, according to the activationtime, a time for sending the random access resource allocation message.

A secondary base station device, including:

a twelfth sending unit, configured to, after sending a secondary servingcell addition response message to a primary base station, send a randomaccess resource allocation message to a terminal, where the secondaryserving cell addition response message includes a cell radio networktemporary identifier of the terminal and the random access resourceallocation message includes a serial number of a random access preamblecode and a serial number of a physical random access channel mask code;

a fifteenth receiving unit, configured to receive a random accessrequest message that is sent by the terminal and carries the randomaccess preamble code obtained according to the serial number of therandom access preamble code; and

a thirteenth sending unit, configured to obtain a time advance commandTAC according to the random access request message, and send, to theterminal, a random access response message that carries the TAC, so thatthe terminal adjusts, according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

According to the foregoing secondary base station device, the secondaryserving cell addition response message further includes activation time,and the secondary base station determines, according to the activationtime, a time for sending the random access resource allocation message.

An embodiment of the present invention still provides a network system,and the network system includes the terminal, the secondary basestation, and the primary base station provided in the foregoingembodiments.

An embodiment of the present invention still provides a network system,and the network system includes the terminal device, the secondary basestation device, and the primary base station device provided in theforegoing embodiments.

According to the method for adding a secondary serving cell, theapparatus, the device, and the network system that are provided in theembodiments of the present invention, a unified serial number of arandom access preamble code, a unified serial number of a PRACH maskcode, and a unified cell radio network temporary identifier of aterminal are acquired by means of mutual communication between a primarybase station and a secondary base station, and the serial number of therandom access preamble code and the serial number of the PRACH mask codeare scrambled by using the cell radio network temporary identifier ofthe terminal, and are then sent to the terminal, so that after using thecell radio network temporary identifier to descramble the serial numberof a random access preamble code and the serial number of a PRACH maskcode, the terminal learns about a random access preamble code and sendsthe random access preamble code to the secondary base station. Thesecondary base station determines a time advance command TAC accordingto a random access request message that carries the random accesspreamble code, and sends the time advance command TAC to the terminal,so that the terminal adjusts time advance TA of the terminal on asecondary serving cell corresponding to the secondary base station. Byimplementing technical solutions provided in the embodiments of thepresent invention, a primary serving cell and a secondary serving cellcan still work properly when the primary serving cell and the secondaryserving cell separately belong to different base stations, or a delayover a connection between the primary serving cell and the secondaryserving cell is relatively long and a capacity is relatively small.

BRIEF DESCRIPTION OF DRAWINGS

To describe the technical solutions in the embodiments of the presentinvention more clearly, the following briefly introduces theaccompanying drawings required for describing the embodiments.Apparently, the accompanying drawings in the following description showsome embodiments of the present invention, and persons of ordinary skillin the art may still derive other drawings from these accompanyingdrawings without creative efforts.

FIG. 1 is a schematic signaling diagram of a network system;

FIG. 2 is a schematic signaling diagram of a network system;

FIG. 3 is a schematic flowchart 1 of an embodiment of a method foradding a secondary serving cell according to the present invention;

FIG. 4 is a schematic flowchart 2 of an embodiment of a method foradding a secondary serving cell according to the present invention;

FIG. 5 is a schematic flowchart 3 of an embodiment of a method foradding a secondary serving cell according to the present invention;

FIG. 6 is a schematic diagram of signaling of a first embodiment of anetwork system according to the present invention;

FIG. 7 is a schematic structural diagram 1 of an apparatus embodimentfor adding a secondary serving cell according to the present invention;

FIG. 8 is a schematic structural diagram 2 of an apparatus embodimentfor adding a secondary serving cell according to the present invention;

FIG. 9 is a schematic structural diagram 3 of an apparatus embodimentfor adding a secondary serving cell according to the present invention;

FIG. 10 is a schematic structural diagram 1 of a device embodiment foradding a secondary serving cell according to the present invention;

FIG. 11 is a schematic structural diagram 2 of a device embodiment foradding a secondary serving cell according to the present invention;

FIG. 12 is a schematic structural diagram 3 of a device embodiment foradding a secondary serving cell according to the present invention;

FIG. 13 is a schematic structural diagram 1 of an embodiment of anetwork system according to the present invention;

FIG. 14 is a schematic structural diagram 2 of an embodiment of anetwork system according to the present invention;

FIG. 15 is a schematic flowchart 4 of an embodiment of a method foradding a secondary serving cell according to the present invention;

FIG. 16 is a schematic flowchart 5 of an embodiment of a method foradding a secondary serving cell according to the present invention;

FIG. 17 is a schematic signaling diagram of a second embodiment of anetwork system according to the present invention;

FIG. 18 is a schematic signaling diagram of a third embodiment of anetwork system according to the present invention;

FIG. 19 is a schematic flowchart 6 of an embodiment of a method foradding a secondary serving cell according to the present invention;

FIG. 20 is a schematic signaling diagram of a fourth embodiment of anetwork system according to the present invention;

FIG. 21 is a schematic signaling diagram of a fifth embodiment of anetwork system according to the present invention;

FIG. 22 is a schematic structural diagram 4 of an apparatus embodimentfor adding a secondary serving cell according to the present invention;

FIG. 23 is a schematic structural diagram 5 of an apparatus embodimentfor adding a secondary serving cell according to the present invention;

FIG. 24 is a schematic structural diagram 6 of an apparatus embodimentfor adding a secondary serving cell according to the present invention;

FIG. 25 is a schematic structural diagram 4 of a device embodiment foradding a secondary serving cell according to the present invention;

FIG. 26 is a schematic structural diagram 5 of a device embodiment foradding a secondary serving cell according to the present invention;

FIG. 27 is a schematic structural diagram 6 of a device embodiment foradding a secondary serving cell according to the present invention;

FIG. 28 is a schematic structural diagram 3 of an embodiment of anetwork system according to the present invention;

FIG. 29 is a schematic structural diagram 4 of an embodiment of anetwork system according to the present invention;

FIG. 30 is a schematic flowchart 7 of an embodiment of a method foradding a secondary serving cell according to the present invention;

FIG. 31 is a schematic flowchart 8 of an embodiment of a method foradding a secondary serving cell according to the present invention;

FIG. 32 is a schematic signaling diagram of a sixth embodiment of anetwork system according to the present invention;

FIG. 33 is a schematic flowchart 9 of an embodiment of a method foradding a secondary serving cell according to the present invention;

FIG. 34 is a schematic signaling diagram of a seventh embodiment of anetwork system according to the present invention;

FIG. 35 is a schematic structural diagram 7 of an apparatus embodimentfor adding a secondary serving cell according to the present invention;

FIG. 36 is a schematic structural diagram 8 of an apparatus embodimentfor adding a secondary serving cell according to the present invention;

FIG. 37 is a schematic structural diagram 9 of an apparatus embodimentfor adding a secondary serving cell according to the present invention;

FIG. 38 is a schematic structural diagram 7 of a device embodiment foradding a secondary serving cell according to the present invention;

FIG. 39 is a schematic structural diagram 8 of a device embodiment foradding a secondary serving cell according to the present invention;

FIG. 40 is a schematic structural diagram 9 of a device embodiment foradding a secondary serving cell according to the present invention;

FIG. 41 is a schematic structural diagram 5 of an embodiment of anetwork system according to the present invention; and

FIG. 42 is a schematic structural diagram 6 of an embodiment of anetwork system according to the present invention.

DESCRIPTION OF EMBODIMENTS

To make the objectives, technical solutions, and advantages of theembodiments of the present invention clearer, the following clearlydescribes the technical solutions in the embodiments of the presentinvention with reference to the accompanying drawings in the embodimentsof the present invention. Apparently, the described embodiments are apart rather than all of the embodiments of the present invention. Allother embodiments obtained by persons of ordinary skill in the art basedon the embodiments of the present invention without creative effortsshall fall within the protection scope of the present invention.

The following further describes the present invention in detail by usingspecific embodiments and with reference to accompanying drawings.

FIG. 3 is a schematic flowchart 1 of an embodiment of a method foradding a secondary serving cell according to the present invention. Themethod applies to a terminal, and includes the following steps:

Step 1101: The terminal receives a random access resource allocationmessage sent by a primary base station, where the random access resourceallocation message includes a serial number of a random access preamblecode and a serial number of a physical random access channel mask code.

Specifically, the terminal in this embodiment of the present inventiongains contact first with the primary base station. A cell in which theterminal is located may be a primary serving cell to which the primarybase station belongs or may be a secondary serving cell to which thesecondary base station belongs. When the terminal is in the secondaryserving cell, to prevent a problem from occurring during communicationbetween the terminal and the secondary base station, the secondary basestation needs to communicate with the primary base station to acquiresame signaling, so that the terminal can also communicate with thesecondary base station properly. First, the primary base station sendsthe random access resource allocation message to the terminal, where therandom access resource allocation message includes the serial number ofthe random access preamble code and the serial number of the PRACH maskcode.

Step 1102: The terminal sends a random access request message to asecondary base station by using a sending resource that is determinedaccording to the serial number of the physical random access channelmask code, where the random access request message includes the randomaccess preamble code that is determined according to the serial numberof the random access preamble code.

Specifically, the terminal determines, according to the serial number ofthe PRACH mask code, the resource for sending the random access requestmessage to the secondary base station. The terminal further determines,according to the received serial number of the random access preamblecode, the random access preamble code sent to the secondary basestation.

Step 1103: The terminal receives a random access response message sentby the primary base station, where the random access response messageincludes a time advance command TAC that is sent by the secondary basestation to the primary base station and is determined by the secondarybase station according to the random access request message.

Specifically, the terminal receives the time advance command TAC sent bythe primary base station, where the time advance command TAC is sent bythe secondary base station to the primary base station and the timeadvance command TAC is determined by the secondary base stationaccording to the random access request message that is sent by theterminal.

Step 1104: The terminal adjusts, according to the TAC, time advance TAof the terminal on a secondary serving cell corresponding to thesecondary base station.

Specifically, the terminal adjusts, according to the received timeadvance command TAC, the time advance TA of the terminal on thecorresponding cell.

Further, before the terminal receives the random access resourceallocation message sent by the primary base station, the terminalfurther receives a cell radio network temporary identifier sent by theprimary base station; and after the terminal receives the random accessresource allocation message sent by the primary base station, theterminal uses the cell radio network temporary identifier of theterminal to descramble the random access resource allocation message.

Specifically, the cell radio network temporary identifier is sent by theprimary base station to the terminal in advance. That is, before theterminal receives the serial number of the random access preamble codeand the serial number of the physical random access channel mask codesent by the primary base station, the terminal has received the cellradio network temporary identifier sent by the primary base station, andthe terminal uses the cell radio network temporary identifier todescramble the received random access resource allocation message, toobtain the serial number of the random access preamble code and theserial number of the physical random access channel mask code.

FIG. 4 is a schematic flowchart 2 of an embodiment of a method foradding a secondary serving cell according to the present invention. Themethod applies to a primary base station, and includes the followingsteps:

Step 1201: The primary base station sends a random access resourceallocation message and a secondary serving cell addition request messageto a terminal and a secondary base station, respectively, where both therandom access resource allocation message and the secondary serving celladdition request message include a serial number of a random accesspreamble code and a serial number of a physical random access channelmask code.

Specifically, the primary base station sends the serial number of therandom access preamble code and the serial number of the PRACH mask codeto the secondary base station, and the primary base station also sendsthe same serial number of the random access preamble code and serialnumber of the PRACH mask code to the terminal.

Step 1202: The primary base station receives a time advance command TACtransmission message sent by the secondary base station, where the TACtransmission message is sent to the primary base station after thesecondary base station receives a random access request message that issent by the terminal and carries the random access preamble codeobtained according to the serial number of the random access preamblecode; and the TAC transmission message includes a TAC obtained by thesecondary base station according to the random access request message.

Specifically, the primary base station receives the time advance commandTAC transmission message sent by the secondary base station, where thetime advance command TAC transmission message is sent by secondary basestation to the primary base station and the time advance command TACtransmission message is determined by the secondary base stationaccording to the random access request message that is sent by theterminal to the secondary base station and carries the random accesspreamble code. The time advance command TAC transmission messageincludes the TAC that is obtained by the secondary base stationaccording to the random access request message.

Step 1203: The primary base station sends, to the terminal, a randomaccess response message that carries the TAC, so that the terminaladjusts, according to the TAC, time advance TA of the terminal on asecondary serving cell corresponding to the secondary base station.

Specifically, the primary base station sends the TAC to the terminal, sothat the terminal adjusts, according to the TAC, the time advance TA ofthe terminal on the secondary serving cell corresponding to thesecondary base station.

Further, before sending the random access resource allocation message tothe terminal, the primary base station further sends a cell radionetwork temporary identifier of the terminal to the terminal; and theprimary base station uses the cell radio network temporary identifier ofthe terminal to scramble the random access resource allocation message,and then sends the random access resource allocation message to theterminal.

Specifically, before sending the random access resource allocationmessage to the terminal, the primary base station further sends the cellradio network temporary identifier of the terminal to the terminal; andthe primary base station applies the cell radio network temporaryidentifier to scramble the random access resource allocation message,and then sends the random access resource allocation message to theterminal.

Further, the time advance command TAC transmission message received bythe primary base station includes a first time at which the secondarybase station receives the random access request message; and the primarybase station determines, according to the first time, a second time forsending the random access response message.

Specifically, a time at which the secondary base station receives therandom access request message sent by the terminal is the first time,and the primary base station determines, according to the first time,that a time for sending the random access response message to theterminal is the second time.

FIG. 5 is a schematic flowchart 3 of an embodiment of a method foradding a secondary serving cell according to the present invention. Themethod applies to a secondary base station, and includes the followingsteps:

Step 1301: The secondary base station receives a secondary serving celladdition request message sent by a primary base station, where thesecondary serving cell addition request message includes a serial numberof a random access preamble code and a serial number of a physicalrandom access channel mask code.

Specifically, the secondary base station receives the serial number ofthe random access preamble code and the serial number of the PRACH maskcode sent by the primary base station.

Step 1302: The secondary base station receives, according to thesecondary serving cell addition request message, a random access requestmessage that is sent by a terminal and carries the random accesspreamble code obtained according to the serial number of the randomaccess preamble code.

Specifically, the secondary base station determines, according to thereceived serial number of the random access preamble code and serialnumber of the physical random access channel mask code, the randomaccess preamble code sent by the terminal, where the random accesspreamble code is determined by the serial number of the random accesspreamble code.

Step 1303: The secondary base station obtains a time advance command TACaccording to the random access request message, and sends, to theprimary base station, a time advance command TAC transmission messagethat carries the TAC, so that the primary base station sends, to theterminal, a random access response message that carries the TAC so thatthe terminal adjusts, according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

Specifically, the secondary base station determines the time advancecommand TAC according to the received random access request message, andsends, to the primary base station, the transmission message thatcarries the time advance command TAC, so that the primary base stationdetermines, according to the time advance command TAC, a TAC sent to theterminal so that the terminal adjusts, according to the TAC, the timeadvance TA of the terminal on the secondary serving cell correspondingto the secondary base station.

Further, the time advance command TAC transmission message sent by thesecondary base station further includes a first time at which thesecondary base station receives the random access request message, sothat the primary base station determines, according to the first time, asecond time for sending the random access response message.

Specifically, a time at which the secondary base station receives therandom access request message sent by the terminal is the first time,and the primary base station determines, according to the first time,that a time for sending the random access response message to theterminal is the second time.

FIG. 6 is a schematic signaling diagram of a first embodiment of anetwork system according to the present invention. As shown in FIG. 6,transmission of the signaling is divided into five steps. Step 1: Aprimary base station sends a secondary serving cell addition requestmessage to a secondary base station. Step 2: The primary base stationsends a random access resource allocation message to a terminal. Boththe secondary serving cell addition request message and the randomaccess resource allocation message include a serial number of a randomaccess preamble code and a serial number of a PRACH mask code, and step1 and step 2 may be interchangeable. Step 3: The terminal sends a randomaccess request message to the secondary base station according to therandom access resource allocation message that is sent by the primarybase station, where the random access request message includes a randomaccess preamble code. Step 4: The secondary base station sends a timeadvance command TAC transmission message to the primary base stationaccording to the received random access request message, where the timeadvance command TAC transmission message includes a first time at whichthe secondary base station receives the random access request message,and the primary base station determines, according to the first time, asecond time for sending a random access response message. Step 5: Theprimary base station sends, to the terminal, the random access responsemessage according to the received time advance command TAC transmissionmessage, where the random access response message includes a timeadvance command TAC that is sent by the secondary base station to theprimary base station and is determined according to the random accessrequest message sent by the terminal, so that the terminal adjusts,according to the received random access response message, time advanceTA of the terminal on a corresponding cell. Before step 2, the terminalfurther receives a cell radio network temporary identifier sent by theprimary base station; the primary base station uses the cell radionetwork temporary identifier to scramble the random access resourceallocation message, and then sends the random access resource allocationmessage to the terminal; and the terminal uses the cell radio networktemporary identifier to descramble the received random access resourceallocation message.

According to the method for adding a secondary serving cell, theapparatus, the device, and the network system that are provided in theembodiments of the present invention, a primary base station sends asecondary serving cell addition request message to a secondary basestation, so that the secondary base station can correctly receive arandom access request message sent by a terminal; and then the secondarybase station sends a time advance command transmission message to theprimary base station according to the received random access requestmessage, thereby ensuring that the primary base station can determinecontent of a random access response message and a time for sending themessage to the terminal according to the transmission message. Accordingto the embodiments of the present invention, a primary serving cell anda secondary serving cell can still work properly when the primaryserving cell and the secondary serving cell belong to different basestations, or a delay over a connection between the primary serving celland the secondary serving cell is relatively long and a capacity isrelatively small.

FIG. 7 is a schematic structural diagram 1 of an apparatus embodimentfor adding a secondary serving cell according to the present invention.As shown in FIG. 7, a terminal includes a first unit 111A, a second unit112A, a third unit 113A, and a fourth unit 114A. The first unit 111A isconfigured to receive a random access resource allocation message sentby a primary base station, where the random access resource allocationmessage includes a serial number of a random access preamble code and aserial number of a physical random access channel mask code. The secondunit 112A is configured to send a random access request message to asecondary base station by using a sending resource that is determinedaccording to the serial number of the physical random access channelmask code, where the random access request message includes the randomaccess preamble code that is determined according to the serial numberof the random access preamble code. The third unit 113A is configured toreceive a random access response message sent by the primary basestation, where the random access response message includes a timeadvance command TAC that is sent by the secondary base station to theprimary base station and is determined by the secondary base stationaccording to the random access request message. The fourth unit 114A isconfigured to adjust, according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

Further, before the first unit 111A receives the random access resourceallocation message sent by the primary base station, the terminalfurther receives a cell radio network temporary identifier of theterminal sent by the primary base station. After receiving the randomaccess resource allocation message sent by the primary base station, theterminal uses the cell radio network temporary identifier of theterminal to descramble the random access resource allocation message.

FIG. 8 is a schematic structural diagram 2 of an apparatus embodimentfor adding a secondary serving cell according to the present invention.As shown in FIG. 8, the primary base station includes a fifth unit 121A,a sixth unit 122A, and a seventh unit 123A. The fifth unit 121A isconfigured to send a random access resource allocation message and asecondary serving cell addition request message to a terminal and asecondary base station, respectively, and both the random accessresource allocation message and the secondary serving cell additionrequest message include a serial number of a random access preamble codeand a serial number of a physical random access channel mask code. Thesixth unit 122A is configured to receive a time advance command TACtransmission message sent by the secondary base station, where the TACtransmission message is sent to the primary base station after thesecondary base station receives a random access request message that issent by the terminal and carries the random access preamble codeobtained according to the serial number of the random access preamblecode; and the TAC transmission message includes a TAC obtained by thesecondary base station according to the random access request message.The seventh unit 123A is configured to send, to the terminal, a randomaccess response message that carries the TAC, so that the terminaladjusts, according to the TAC, time advance TA of the terminal on asecondary serving cell corresponding to the secondary base station.

Further, before sending the random access resource allocation message tothe terminal, the fifth unit 121A further sends a cell radio networktemporary identifier of the terminal to the terminal; the primary basestation uses the cell radio network temporary identifier of the terminalto scramble the random access resource allocation message, and thensends the random access resource allocation message to the terminal.

Further, according to the foregoing primary base station, the timeadvance command TAC transmission message includes a first time at whichthe secondary base station receives the random access request message;and the seventh unit is further configured to determine, according tothe first time, a second time for sending the random access responsemessage.

FIG. 9 is a schematic structural diagram 3 of an apparatus embodimentfor adding a secondary serving cell according to the present invention.As shown in FIG. 9, a secondary base station includes an eighth unit131A, a ninth unit 132A, and a tenth unit 133A. The eighth unit 131A isconfigured to receive a secondary serving cell addition request messagesent by a primary base station, where the secondary serving celladdition request message includes a serial number of a random accesspreamble code and a serial number of a physical random access channelmask code. The ninth unit 132A is configured to receive, according tothe secondary serving cell addition request message, a random accessrequest message that is sent by a terminal and carries the random accesspreamble code. The tenth unit 133A is configured to obtain a timeadvance command TAC according to the random access request message, andsend, to the primary base station, a time advance command TACtransmission message that carries the TAC, so that the primary basestation sends, to the terminal, a random access response message thatcarries the TAC so that the terminal adjusts, according to the TAC, timeadvance TA of the terminal on a secondary serving cell corresponding tothe secondary base station.

Further, according to the foregoing secondary base station, the timeadvance command TAC transmission message includes a first time at whichthe secondary base station receives the random access request message,so that the primary base station determines, according to the firsttime, a second time for sending the random access response message.

An embodiment of the present invention provides a terminal device. FIG.10 is a schematic structural diagram 1 of a device embodiment for addinga secondary serving cell according to the present invention. As shown inFIG. 10, the terminal device includes a first receiving unit 111B, afirst sending unit 112B, a second receiving unit 113B, and a firstprocessing unit 114B. The first receiving unit 111B is configured toreceive a random access resource allocation message sent by a primarybase station, where the random access resource allocation messageincludes a serial number of a random access preamble code and a serialnumber of a physical random access channel mask code. The first sendingunit 112B is configured to send a random access request message to asecondary base station by using a sending resource that is determinedaccording to the serial number of the physical random access channelmask code, where the random access request message includes the randomaccess preamble code that is determined according to the serial numberof the random access preamble code. The second receiving unit 113B isconfigured to receive a random access response message sent by theprimary base station, where the random access response message includesa time advance command TAC that is sent by the secondary base station tothe primary base station and is determined by the secondary base stationaccording to the random access request message. The first processingunit 114B is configured to adjust, according to the TAC, time advance TAof the terminal on a secondary serving cell corresponding to thesecondary base station.

An embodiment of the present invention provides a primary base stationdevice. FIG. 11 is a schematic structural diagram 2 of a deviceembodiment for adding a secondary serving cell according to the presentinvention. As shown in FIG. 11, the primary base station device includesa second sending unit 121B, a third receiving unit 122B, and a thirdsending unit 123B. The second sending unit 121B is configured to send arandom access resource allocation message and a secondary serving celladdition request message to a terminal and a secondary base station,respectively, where both the random access resource allocation messageand the secondary serving cell addition request message include a serialnumber of a random access preamble code and a serial number of aphysical random access channel mask code. The third receiving unit 122Bis configured to receive a time advance command TAC transmission messagesent by the secondary base station, where the TAC transmission messageis sent to the primary base station after the secondary base stationreceives a random access request message that is sent by the terminaland carries the random access preamble code obtained according to theserial number of the random access preamble code; and the TACtransmission message includes a TAC obtained by the secondary basestation according to the random access request message. The thirdsending unit 123B is configured to send, to the terminal, a randomaccess response message that carries the TAC, so that the terminaladjusts, according to the TAC, time advance TA of the terminal on asecondary serving cell corresponding to the secondary base station.

Further, according to the foregoing primary base station device, thetime advance command TAC transmission message further includes a firsttime at which the secondary base station receives the random accessrequest message.

Correspondingly, the third sending unit is further configured todetermine, according to the first time, a second time for sending therandom access response message.

An embodiment of the present invention provides a secondary base stationdevice. FIG. 12 is a schematic structural diagram 3 of a deviceembodiment for adding a secondary serving cell according to the presentinvention. As shown in FIG. 12, the secondary base station deviceincludes a fourth receiving unit 131B, a fifth receiving unit 132B, anda fourth sending unit 133B. The fourth receiving unit 131B is configuredto receive a secondary serving cell addition request message sent by aprimary base station, where the secondary serving cell addition requestmessage includes a serial number of a random access preamble code and aserial number of a physical random access channel mask code. The fifthreceiving unit 132B is configured to receive, according to the secondaryserving cell addition request message, a random access request messagethat is sent by a terminal and carries the random access preamble code.The fourth sending unit 133B is configured to obtain a time advancecommand TAC according to the random access request message, and send, tothe primary base station, a time advance command TAC transmissionmessage that carries the TAC, so that the primary base station sends, tothe terminal, a random access response message that carries the TAC sothat the terminal adjusts, according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

Further, according to the foregoing secondary base station device, thetime advance command TAC transmission message further includes a firsttime at which the secondary base station receives the random accessrequest message, so that the primary base station determines, accordingto the first time, a second time for sending the random access responsemessage.

FIG. 13 is a schematic structural diagram 1 of an embodiment of anetwork system according to the present invention. As shown in FIG. 13,the system includes a terminal 11A, a primary base station 12A, and asecondary base station 13A. The terminal 11A receives a cell radionetwork temporary identifier of the terminal sent by the primary basestation 12A, uses the cell radio network temporary identifier todescramble a subsequently received random access resource allocationmessage, and sends a random access request message to the secondary basestation 13A according to a descrambled random access resource allocationmessage. Then, the terminal 11A receives a random access responsemessage sent by the primary base station 12A, and adjusts, according tothe random access response message received by the terminal 11A, timeadvance TA of the terminal 11A on a corresponding cell. The primary basestation 12A sends a secondary serving cell addition request message tothe secondary base station 13A. Before sending the random accessresource allocation message to the terminal 11A, the primary basestation 12A further sends the cell radio network temporary identifier ofthe terminal to the terminal, the primary base station scrambles therandom access resource allocation message according to the cell radionetwork temporary identifier and sends a scrambled random accessresource allocation message to the terminal again, and the primary basestation 12A sends the random access response message to the terminal 11Aaccording to the received time advance command transmission message. Thesecondary base station 13A receives the secondary serving cell additionrequest message sent by the primary base station 12A, and the secondarybase station 13A sends the time advance command TAC transmission messageto the primary base station 12A according to the received random accessrequest message.

FIG. 14 is a schematic structural diagram 2 of an embodiment of anetwork system according to the present invention. As shown in FIG. 14,the system includes a terminal device 11B, a primary base station device12B, and a secondary base station device 13B. The devices are configuredto correspondingly execute the technical solution of the apparatusembodiment shown in FIG. 13. A principle and a technical effect thereofare similar, and details are not described herein again.

FIG. 15 is a schematic flowchart 4 of an embodiment of a method foradding a secondary serving cell according to the present invention. Themethod applies to a terminal, and includes the following steps:

Step 2101: The terminal receives a notification message sent by aprimary base station, where the notification message includes a serialnumber of a random access preamble code and a serial number of aphysical random access channel mask code.

Specifically, the terminal receives the serial number of the randomaccess preamble code and the serial number of the PRACH mask code sentby the primary base station.

Step 2102: The terminal sends a random access request message to asecondary base station by using a sending resource that is determinedaccording to the serial number of the physical random access channelmask code, where the random access request message includes the randomaccess preamble code that is determined according to the serial numberof the random access preamble code.

Specifically, the terminal determines, according to the received serialnumber of the PRACH mask code, the resource for sending the randomaccess request message to the secondary base station. The terminalfurther determines, according to the received serial number of therandom access preamble code, the random access preamble code sent to thesecondary base station.

Step 2103: The terminal receives a random access response message sentby the secondary base station, where the random access response messageincludes a time advance command TAC that is determined by the secondarybase station according to the random access request message.

Specifically, the terminal receives the time advance command TAC sent bythe secondary base station, where the time advance command TAC isdetermined by the secondary base station according to the receivedrandom access request message.

Step 2104: The terminal adjusts, according to the TAC, time advance TAof the terminal on a secondary serving cell corresponding to thesecondary base station.

Specifically, the terminal adjusts, according to the time advancecommand TAC sent by the secondary base station, the time advance TA ofthe terminal on the corresponding cell.

Further, according to the terminal in the foregoing method for adding asecondary serving cell, the notification message may be areconfiguration message, and the reconfiguration message furtherincludes a random access response window size, of the secondary servingcell, that is used by the terminal to receive the random access responsemessage. The notification message may also be a random access resourceallocation message. When the notification message is a random accessresource allocation message, the terminal may further receive areconfiguration message sent by the primary base station, where thereconfiguration message includes a random access response window size,of the secondary serving cell, that is used by the terminal to receivethe random access response message.

Specifically, in addition to receiving the serial number of the randomaccess preamble code and the serial number of the PRACH mask code sentby the primary base station, the terminal further receives a responsewindow size sent by the primary base station, and the terminaldetermines, according to the response window size, a time window forreceiving the random access response message. The terminal may receive,in one step, the response window size, the serial number of the randomaccess preamble code, and the serial number of the PRACH mask code sentby the primary base station, or may receive, in two steps, the responsewindow size, the serial number of the random access preamble code, andthe serial number of the PRACH mask code sent by the primary basestation. Specifically, when the notification message received by theterminal is a reconfiguration message, the notification message includesthe following information: the serial number of the random accesspreamble code, the serial number of the PRACH mask code, and the randomaccess response window size, of the secondary serving cell, that is usedby the terminal to receive the random access response message, and isincluded in the reconfiguration message. When the notification messagereceived by the terminal is a random access resource allocation message,the notification message includes the following information: the serialnumber of the random access preamble code and the serial number of thePRACH mask code. In addition, the notification message further includesa random access response window size used by the terminal to receive therandom access response message, is of the secondary serving cell, and isincluded in the reconfiguration message.

Still further, according to the terminal in the foregoing method foradding a secondary serving cell, before the terminal receives thenotification message sent by the primary base station, the terminalfurther receives a cell radio network temporary identifier of theterminal sent by the primary base station; and after receiving thenotification message sent by the primary base station, the terminal usesthe cell radio network temporary identifier of the terminal to performdescrambling, to obtain the serial number of the random access preamblecode and the serial number of the physical random access channel maskcode.

Specifically, before the terminal receives the serial number of therandom access preamble code and the serial number of the PRACH mask codesent by the primary base station, the terminal further receives the cellradio network temporary identifier of the terminal sent by the primarybase station, and the terminal uses the cell radio network temporaryidentifier to descramble the received random access resource allocationmessage, to obtain the serial number of the random access preamble codeand the serial number of the physical random access channel mask code.

FIG. 16 is a schematic flowchart 5 of an embodiment of a method foradding a secondary serving cell according to the present invention. Themethod applies to a secondary base station, and includes the followingsteps:

Step 2301: The secondary base station receives a secondary serving celladdition request message sent by a primary base station, where thesecondary serving cell addition request message includes a serial numberof a random access preamble code and a serial number of a physicalrandom access channel mask code.

Specifically, the secondary base station receives the serial number ofthe random access preamble code and the serial number of the physicalrandom access channel mask code sent by the primary base station.

Step 2302: The secondary base station receives, according to thesecondary serving cell addition request message, a random access requestmessage that is sent by a terminal and carries the random accesspreamble code obtained according to the serial number of the randomaccess preamble code.

Specifically, the secondary base station receives, according to theserial number of the random access preamble code and the serial numberof the physical random access channel mask code sent by the primary basestation, the random access request message sent by the terminal, wherethe random access preamble code included in the random access requestmessage is determined by the serial number of the random access preamblecode.

Step 2303: The secondary base station obtains a time advance command TACaccording to the random access request message, and sends, to theterminal, a random access response message that carries the TAC, so thatthe terminal adjusts, according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

Specifically, the secondary base station determines the time advancecommand TAC according to the received random access request message, andsends the time advance command TAC to the terminal. The terminaladjusts, according to the TAC, time advance TA of the terminal on acorresponding cell.

FIG. 17 is a schematic signaling diagram of a second embodiment of anetwork system according to the present invention. As shown in FIG. 17,transmission of the signaling is divided into five steps. Step 1: Aprimary base station sends a secondary serving cell addition requestmessage to a secondary base station, where the secondary serving celladdition request message includes a serial number of a random accesspreamble code and a serial number of a PRACH mask code. Step 2: Theprimary base station sends a reconfiguration message to a terminal,where the reconfiguration message includes a response window size. Step3: The primary base station sends a random access resource allocationmessage to the terminal, where the random access resource allocationmessage includes a serial number of a random access preamble code and aserial number of a PRACH mask code. Step 4: The terminal sends a randomaccess request message to the secondary base station according to thereceived random access resource allocation message, where the randomaccess request message includes a random access preamble code. Step 5:The secondary base station sends a random access response message to theterminal according to the received random access request message, wherethe random access response message includes a time advance command TAC,so that the terminal adjusts, according to the time advance command TAC,time advance TA of the terminal on a corresponding cell, where theterminal determines, according to the response window size included inthe received reconfiguration message, a time window for receiving therandom access response message to receive the random access responsemessage. Step 2 is optional. When step 2 is skipped, the terminal uses adefault time window to receive the random access response message. Inaddition, before the terminal receives the random access resourceallocation message sent by the primary base station, the terminalfurther receives a cell radio network temporary identifier of theterminal sent by a the primary base station, so that the primary basestation uses the cell radio network temporary identifier to scramble therandom access resource allocation message and then sends a scrambledrandom access resource allocation message to the terminal, and so thatthe terminal uses the cell radio network temporary identifier todescramble a subsequently received random access resource allocationmessage, where the cell radio network temporary identifier is allocatedby the primary base station to the terminal in advance.

According to the method for adding a secondary serving cell, theapparatus, the device, and the network system that are provided in theembodiments of the present invention, a primary base station sends asecondary serving cell addition request message to a secondary basestation, so that the secondary base station can correctly receive, in asubsequent step, a random access request message sent by a terminal, anddetermine content of a random access response message and a time forsending the message to the terminal. According to the embodiments of thepresent invention, a primary serving cell and a secondary serving cellcan still work properly in a case in which the primary serving cell andthe secondary serving cell belong to different base stations, or when adelay over a connection between the primary serving cell and thesecondary serving cell is relatively long and a capacity is relativelysmall.

FIG. 18 is a schematic diagram of signaling of a third embodiment of anetwork system according to the present invention. As shown in FIG. 18,transmission of the signaling is divided into four steps. Step 1: Aprimary base station sends a secondary serving cell addition requestmessage to a secondary base station, where the secondary serving celladdition request message includes a serial number of a random accesspreamble code and a serial number of a PRACH mask code. Step 2: Theprimary base station sends a reconfiguration message to a terminal,where the reconfiguration message includes a serial number of a randomaccess preamble code and a serial number of a PRACH mask code, andoptionally, the reconfiguration message further includes a responsewindow size. Steps 3 and 4 are the same as steps 4 and 5 in theschematic signaling diagram of the second embodiment, and details arenot described herein again. When the response window size is notincluded in the reconfiguration message, the terminal uses a defaulttime window to receive a random access response message. In addition,before the terminal receives the reconfiguration message sent by theprimary base station, the terminal further receives a cell radio networktemporary identifier of the terminal sent by the primary base station,so that the primary base station uses the cell radio network temporaryidentifier to scramble a random access resource allocation message andthen sends a scrambled random access resource allocation message to theterminal, so that the terminal uses the cell radio network temporaryidentifier to descramble a subsequently received random access resourceallocation message. That is, the cell radio network temporary identifieris allocated by the primary base station to the terminal in advance.

According to the method for adding a secondary serving cell, theapparatus, the device, and the network system that are provided in theembodiments of the present invention, a primary base station sends asecondary serving cell addition request message to a secondary basestation, so that the secondary base station can correctly receive, in asubsequent step, a random access request message sent by a terminal, andthen determine content of a random access response message and a timefor sending the message to the terminal. According to the embodiments ofthe present invention, a primary serving cell and a secondary servingcell can still work properly when the primary serving cell and thesecondary serving cell belong to different base stations, or aconnection delay between the primary serving cell and the secondaryserving cell is relatively long and a capacity is relatively small.

FIG. 19 is a schematic flowchart 6 of an embodiment of a method foradding a secondary serving cell according to the present invention. Themethod applies to a secondary base station, and includes the followingsteps:

Step 3301: The secondary base station sends a secondary serving celladdition response message to a primary base station, where the secondaryserving cell addition response message includes a serial number of arandom access preamble code and a serial number of a physical randomaccess channel mask code.

Specifically, the secondary base station sends the serial number of therandom access preamble code and the serial number of the physical randomaccess channel mask code to the primary base station.

Step 3302: The secondary base station receives a random access requestmessage that is sent by a terminal and carries the random accesspreamble code obtained according to the serial number of the randomaccess preamble code.

Specifically, the secondary base station receives, according to theserial number of the random access preamble code and the serial numberof the PRACH mask code that are sent to the primary base station andthen are sent by the primary base station to the terminal, the randomaccess request message sent by the terminal, where the random accesspreamble code carried in the random access request message is determinedby the serial number of the random access preamble code.

Step 3303: The secondary base station obtains a time advance command TACaccording to the random access request message, and sends, to theterminal, a random access response message that carries the TAC, so thatthe terminal adjusts, according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

Specifically, this step is the same as step 2303, and details are notdescribed herein again.

Further, according to the secondary base station in the foregoing methodfor adding a secondary serving cell, the secondary serving cell additionresponse message further includes a random access response window size,of the secondary serving cell, that is used by the terminal to receivethe random access response message.

Specifically, in step 3301, in addition to the serial number of therandom access preamble code and the serial number of the PRACH maskcode, the secondary serving cell addition response message sent by thesecondary base station to the primary base station further includes aresponse window size, and the terminal determines, according to theresponse window size, a time window for receiving the random accessresponse message.

FIG. 20 is a schematic signaling diagram of a fourth embodiment of anetwork system according to the present invention. As shown in FIG. 20,transmission of the signaling is divided into five steps. Step 1: Asecondary base station sends a secondary serving cell addition responsemessage to a primary base station, where the secondary serving celladdition response message includes a serial number of a random accesspreamble code and a serial number of a PRACH mask code. Optionally, thesecondary serving cell addition response message further includes aresponse window size. Steps 2, 3, 4, and 5 are the same as the steps inthe schematic signaling diagram of the second embodiment, and detailsare not described herein again. By comparing the schematic signalingdiagram of the fourth embodiment with the schematic signaling diagram ofthe second embodiment, it is found that the serial number of the randomaccess preamble code, the serial number of the PRACH mask code, and theresponse window size (optional) in the schematic signaling diagram ofthe fourth embodiment are determined by the secondary base station, andthe serial number of the random access preamble code, the serial numberof the PRACH mask code, and the response window size (optional) in theschematic signaling diagram of the second embodiment, however, aredetermined by the primary base station. In addition, step 2 is optional.When step 2 is skipped, the terminal uses a default time window toreceive a random access response message. Before the terminal receivesthe random access resource allocation message sent by the primary basestation, the terminal further receives a cell radio network temporaryidentifier of the terminal sent by a host, so that the primary basestation uses the cell radio network temporary identifier to scramble therandom access resource allocation message and then sends a scrambledrandom access resource allocation message to the terminal, so that theterminal uses the cell radio network temporary identifier to descramblea subsequently received random access resource allocation message. Thatis, the cell radio network temporary identifier is allocated by theprimary base station to the terminal in advance.

According to the method for adding a secondary serving cell, theapparatus, the device, and the network system that are provided in theembodiments of the present invention, a secondary base station sends asecondary serving cell addition response message to a primary basestation, so that after the primary base station sends a random accessresource allocation message to a terminal, it is ensured that thesecondary base station can correctly receive a random access requestmessage sent by the terminal, and the secondary base station then candetermine, according to the random access request message, content of arandom access response message and a time for sending the message to theterminal. According to the embodiments of the present invention, aprimary serving cell and a secondary serving cell can still workproperly in a case in which the primary serving cell and the secondaryserving cell belong to different base stations, or when a delay over aconnection between the primary serving cell and the secondary servingcell is relatively long and a capacity is relatively small.

FIG. 21 is a schematic signaling diagram of a fifth embodiment of anetwork system according to the present invention. As shown in FIG. 21,transmission of the signaling is divided into four steps. Step 1: Asecondary base station sends a secondary serving cell addition responsemessage to a primary base station, where the secondary serving celladdition response message includes a serial number of a random accesspreamble code and a serial number of a PRACH mask code. Optionally, thesecondary serving cell addition response message further includes aresponse window size. Steps 2, 3, and 4 are the same as the steps in theschematic signaling diagram of the third embodiment, and details are notdescribed herein again. By comparing the schematic signaling diagram ofthe fifth embodiment with the schematic signaling diagram of the thirdembodiment, it is found that the serial number of the random accesspreamble code, the serial number of the PRACH mask code, and theresponse window size (optional) in the schematic signaling diagram ofthe fifth embodiment are determined by the secondary base station, andthe serial number of the random access preamble code, the serial numberof the PRACH mask code, and the response window size (optional) in theschematic signaling diagram of the third embodiment, however, aredetermined by the primary base station. When the response window size isnot included in the reconfiguration message, the terminal uses a defaulttime window to receive the random access response message. In addition,before the terminal receives the reconfiguration message sent by theprimary base station, the terminal further receives a cell radio networktemporary identifier of the terminal sent by the primary base station,so that the primary base station uses the cell radio network temporaryidentifier to scramble a random access resource allocation message andthen sends a scrambled random access resource allocation message to theterminal, so that the terminal uses the cell radio network temporaryidentifier to descramble a subsequently received random access resourceallocation message. That is, the cell radio network temporary identifieris allocated by the primary base station to the terminal in advance.

According to the method for adding a secondary serving cell, theapparatus, the device, and the network system that are provided in theembodiments of the present invention, a secondary base station sends asecondary serving cell addition response message to a primary basestation, so that after the primary base station sends a reconfigurationmessage to a terminal, it is ensured that the secondary base station cancorrectly receive a random access request message sent by the terminal,and the secondary base station then can determine, according to therandom access request message, content of a random access responsemessage and a time for sending the message to the terminal. According tothe embodiments of the present invention, a primary serving cell and asecondary serving cell can still work properly in a case in which theprimary serving cell and the secondary serving cell belong to differentbase stations, or when a delay over a connection between the primaryserving cell and the secondary serving cell is relatively long and acapacity is relatively small.

FIG. 22 is a schematic structural diagram 4 of an apparatus embodimentfor adding a secondary serving cell according to the present invention.As shown in FIG. 22, the terminal includes an eleventh unit 211A, atwelfth unit 212A, a thirteenth unit 213A, and a fourteenth unit 214A.The eleventh unit 211A is configured to receive a notification messagesent by a primary base station, where the notification message includesa serial number of a random access preamble code and a serial number ofa physical random access channel mask code. The twelfth unit 212A isconfigured to send a random access request message to a secondary basestation by using a sending resource that is determined according to theserial number of the physical random access channel mask code, where therandom access request message includes the random access preamble codethat is determined according to the serial number of the random accesspreamble code. The thirteenth unit 213A is configured to receive arandom access response message sent by the secondary base station, wherethe random access response message includes a time advance command TACthat is determined by the secondary base station according to the randomaccess request message. The fourteenth unit 214A is configured toadjust, according to the TAC, time advance TA of the terminal on asecondary serving cell corresponding to the secondary base station.

According to the foregoing apparatus for adding a secondary servingcell, the eleventh unit 211A receives the notification message sent bythe primary base station, and the notification message is areconfiguration message or a random access resource allocation message.When the notification message is a random access resource allocationmessage, the terminal further receives a reconfiguration message sent bythe primary base station; and correspondingly, the reconfigurationmessage further includes a random access response window size, of thesecondary serving cell, that is used by the terminal to receive therandom access response message.

Further, before the eleventh unit 211A receives the notificationmessage, the terminal further receives a cell radio network temporaryidentifier of the terminal sent by the primary base station; and afterreceiving the notification message sent by the primary base station, theterminal uses the cell radio network temporary identifier of theterminal to perform descrambling, to obtain the serial number of therandom access preamble code and the serial number of the physical randomaccess channel mask code.

FIG. 23 is a schematic structural diagram 5 of an apparatus embodimentfor adding a secondary serving cell according to the present invention.As shown in FIG. 23, a secondary base station includes a fifteenth unit231A, a sixteenth unit 232A, and a seventeenth unit 233A. The fifteenthunit 231A is configured to receive a secondary serving cell additionrequest message sent by a primary base station, where the secondaryserving cell addition request message includes a serial number of arandom access preamble code and a serial number of a physical randomaccess channel mask code. The sixteenth unit 232A is configured toreceive, according to the secondary serving cell addition requestmessage, a random access request message that is sent by a terminal andcarries the random access preamble code obtained according to the serialnumber of the random access preamble code. The seventeenth unit 233A isconfigured to obtain a time advance command TAC according to the randomaccess request message, and send, to the terminal, a random accessresponse message that carries the TAC, so that the terminal adjusts,according to the TAC, time advance TA of the terminal on a secondaryserving cell corresponding to the secondary base station.

FIG. 24 is a schematic structural diagram 6 of an apparatus embodimentfor adding a secondary serving cell according to the present invention.As shown in FIG. 24, a secondary base station includes an eighteenthunit 331A, a nineteenth unit 332A, and a twentieth unit 333A. Theeighteenth unit 331A is configured to send a secondary serving celladdition response message to a primary base station, where the secondaryserving cell addition response message includes a serial number of arandom access preamble code and a serial number of a physical randomaccess channel mask code. The nineteenth unit 332A is configured toreceive a random access request message that is sent by a terminal andcarries the random access preamble code obtained according to the serialnumber of the random access preamble code. The twentieth unit 333A isconfigured to obtain a time advance command TAC according to the randomaccess request message, and send, to the terminal, a random accessresponse message that carries the TAC, so that the terminal adjusts,according to the TAC, time advance TA of the terminal on a secondaryserving cell corresponding to the secondary base station.

Further, the secondary serving cell addition response message sent bythe eighteenth unit 331A further includes a random access responsewindow size, of the secondary serving cell, that is used for theterminal to receive the random access response message.

An embodiment of the present invention provides a terminal device. FIG.25 is a schematic structural diagram 4 of a device embodiment for addinga secondary serving cell according to the present invention. As shown inFIG. 25, the terminal device includes a sixth receiving unit 211B, afifth sending unit 212B, a seventh receiving unit 213B, and a secondprocessing unit 214B. The sixth receiving unit 211B is configured toreceive a notification message sent by a primary base station, where thenotification message includes a serial number of a random accesspreamble code and a serial number of a physical random access channelmask code. The fifth sending unit 212B is configured to send a randomaccess request message to a secondary base station by using a sendingresource that is determined according to the serial number of thephysical random access channel mask code, where the random accessrequest message includes the random access preamble code that isdetermined according to the serial number of the random access preamblecode. The seventh receiving unit 213B is configured to receive a randomaccess response message sent by the secondary base station, where therandom access response message includes a time advance command TAC thatis determined by the secondary base station according to the randomaccess request message. The second processing unit 214B is configured toadjust, according to the TAC, time advance TA of the terminal on asecondary serving cell corresponding to the secondary base station.

According to the foregoing terminal device, the notification message isa reconfiguration message or a random access resource allocationmessage; when the notification message is a random access resourceallocation message, a terminal device further receives a reconfigurationmessage sent by the primary base station; and correspondingly, thereconfiguration message further includes a random access response windowsize, of the secondary serving cell, that is used by the terminal toreceive the random access response message.

According to the foregoing terminal device, before the terminal receivesthe notification message sent by the primary base station, the terminalfurther receives a cell radio network temporary identifier sent by theprimary base station; and after the terminal receives the notificationmessage sent by the primary base station, the terminal uses the cellradio network temporary identifier to perform descrambling, to obtainthe serial number of the random access preamble code and the serialnumber of the physical random access channel mask code.

FIG. 26 is a schematic structural diagram 5 of a device embodiment foradding a secondary serving cell according to the present invention. Asshown in FIG. 26, a secondary base station device includes an eighthreceiving unit 221B, a ninth receiving unit 222B, and a sixth sendingunit 223B. The eighth receiving unit 221B is configured to receive asecondary serving cell addition request message sent by a primary basestation, where the secondary serving cell addition request messageincludes a serial number of a random access preamble code and a serialnumber of a physical random access channel mask code. The ninthreceiving unit 222B is configured to receive, according to the secondaryserving cell addition request message, a random access request messagethat is sent by a terminal and carries the random access preamble codeobtained according to the serial number of the random access preamblecode. The sixth sending unit 223B is configured to obtain a time advancecommand TAC according to the random access request message, and send, tothe terminal, a random access response message that carries the TAC, sothat the terminal adjusts, according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

FIG. 27 is a schematic structural diagram 6 of a device embodiment foradding a secondary serving cell according to the present invention. Asshown in FIG. 27, the secondary base station device includes a seventhsending unit 231B, a tenth receiving unit 232B, and an eighth sendingunit 233B. The seventh sending unit 231B is configured to send asecondary serving cell addition response message to a primary basestation, where the secondary serving cell addition response messageincludes a serial number of a random access preamble code and a serialnumber of a physical random access channel mask code. The tenthreceiving unit 232B is configured to receive a random access requestmessage that is sent by a terminal and carries the random accesspreamble code obtained according to the serial number of the randomaccess preamble code. The eighth sending unit 233B is configured toobtain a time advance command TAC according to the random access requestmessage, and send, to the terminal, a random access response messagethat carries the TAC, so that the terminal adjusts, according to theTAC, time advance TA of the terminal on a secondary serving cellcorresponding to the secondary base station.

According to the foregoing secondary base station device, the secondaryserving cell addition response message further includes a random accessresponse window size, of the secondary serving cell, that is used by theterminal to receive the random access response message.

FIG. 28 is a schematic structural diagram 3 of an embodiment of anetwork system according to the present invention. As shown in FIG. 28,the network system includes a terminal 21A, a secondary base station23A, and a primary base station 22A. The terminal 21A receives anotification message sent by the primary base station 22A, where thenotification message is a reconfiguration message or a random accessresource allocation message, then sends a random access request messageto the secondary base station 23A according to the received notificationmessage, and then adjusts, according to a received random accessresponse message, time advance TA of the terminal 21A on a correspondingcell. The secondary base station 23A receives a secondary serving celladdition request message sent by the primary base station 22A or sends asecondary serving cell addition response message to the primary basestation 22A, and the secondary base station 23A sends the random accessresponse message to the terminal 21A according to the random accessrequest message sent by the terminal 21A. The primary base station 22Asends the secondary serving cell addition request message to thesecondary base station 23A or receives the secondary serving celladdition response message sent by the secondary base station 23A, andthe secondary base station 23A sends, to the terminal 21A, thereconfiguration message, or the reconfiguration message and the randomaccess resource allocation message.

FIG. 29 is a schematic structural diagram 4 of an embodiment of anetwork system according to the present invention. As shown in FIG. 29,the system includes a terminal device 21B, a primary base station device22B, and a secondary base station device 23B. The devices are configuredto correspondingly execute the technical solution of the apparatusembodiment shown in FIG. 28. A principle and a technical effect thereofare similar, and details are not described herein again.

FIG. 30 is a schematic flowchart 7 of an embodiment of a method foradding a secondary serving cell according to the present invention. Themethod applies to a terminal, and includes the following steps:

Step 3101: The terminal receives a random access resource allocationmessage sent by a secondary base station, where the random accessresource allocation message includes a serial number of a random accesspreamble code and a serial number of a physical random access channelmask code.

Specifically, the terminal receives the serial number of the randomaccess preamble code and the serial number of the physical random accesschannel mask code sent by the secondary base station.

Step 3102: The terminal sends a random access request message to asecondary base station by using a sending resource that is determinedaccording to the serial number of a physical random access channel maskcode, where the random access request message includes the random accesspreamble code that is determined according to the serial number of therandom access preamble code.

Specifically, the terminal determines, according to the serial number ofthe PRACH mask code, the resource for sending the random access requestmessage to the secondary base station. The terminal further determines,according to the received serial number of the random access preamblecode, the random access preamble code sent to the secondary basestation.

Step 3103: The terminal receives a random access response message sentby the secondary base station, where the random access response messageincludes a time advance command TAC that is determined by the secondarybase station according to the random access request message.

Specifically, the terminal receives the time advance command TAC sent bythe secondary base station, where the time advance command TAC isdetermined by the secondary base station according to the receivedrandom access request message.

Step 3104: The terminal adjusts, according to the TAC, time advance TAof the terminal on a secondary serving cell corresponding to thesecondary base station.

Specifically, the terminal adjusts, according to the time advancecommand TAC sent by the secondary base station, the time advance TA ofthe terminal on the corresponding cell.

Further, according to the foregoing method for adding a secondaryserving cell, before step 3101, the terminal further receives a cellradio network temporary identifier of the terminal sent by a primarybase station, and the terminal uses the cell radio network temporaryidentifier to descramble a subsequently received random access resourceallocation message. That is, the cell radio network temporary identifieris allocated by the primary base station to the terminal in advance.

Further, according to the terminal in the foregoing method for adding asecondary serving cell, the method further includes: receiving, by theterminal, a reconfiguration message sent by the primary base station,where the reconfiguration message includes a random access responsewindow size, of the secondary serving cell, that is used by the terminalto receive the random access response message. Alternatively, thereconfiguration message includes the response window size and activationtime, and the terminal determines, according to the activation time, atime for receiving the random access resource allocation message.

Specifically, the terminal receives the random access response windowsize and the activation time sent by the primary base station, where therandom access response window size is a time window at which theterminal receives the random access response message, that is, a periodof time from when the terminal starts receiving the random accessresponse message to when the terminal stops receiving the random accessresponse message is determined. The activation time is a time at whichthe terminal receives the random access resource allocation message.

FIG. 31 is a schematic flowchart 8 of an embodiment of a method foradding a secondary serving cell according to the present invention. Themethod applies to a secondary base station, and includes the followingsteps:

Step 4301: After receiving a secondary serving cell addition requestmessage sent by a primary base station, the secondary base station sendsa random access resource allocation message to a terminal, where thesecondary serving cell addition request message includes a cell radionetwork temporary identifier of the terminal and the random accessresource allocation message includes a serial number of a random accesspreamble code and a serial number of a physical random access channelmask code.

Specifically, after the secondary base station receives the cell radionetwork temporary identifier of the terminal sent by the primary basestation, the secondary base station sends the serial number of therandom access preamble code and the serial number of the physical randomaccess channel mask code to the terminal, and the secondary base stationuses the cell radio network temporary identifier to scramble the serialnumber of the random access preamble code and the serial number of thephysical random access channel mask code.

Step 4302: The secondary base station receives a random access requestmessage that is sent by the terminal and carries the random accesspreamble code obtained according to the serial number of the randomaccess preamble code.

Specifically, the secondary base station receives the random accesspreamble code that is sent by the terminal to the secondary basestation.

Step 4303: The secondary base station obtains a time advance command TACaccording to the random access request message, and sends, to theterminal, a random access response message that carries the TAC, so thatthe terminal adjusts, according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

Specifically, the secondary base station determines, according to thereceived random access request message, the time advance command TACsent to the terminal, so that the terminal adjusts, according to theTAC, the time advance TA of the terminal on the corresponding cell.

Further, according to the secondary base station in the foregoing methodfor adding a secondary serving cell, the secondary serving cell additionrequest message further includes activation time, and the secondary basestation determines, according to the activation time, a time for sendingthe random access resource allocation message.

Specifically, the secondary serving cell addition request message thatis sent by the primary base station and received by the secondary basestation further includes the activation time. That is, in addition toreceiving the cell radio network temporary identifier of the terminalsent by the primary base station, the secondary base station furtherreceives the activation time, where the activation time is used by thesecondary base station to determine the time for sending the randomaccess resource allocation message.

FIG. 32 is a schematic signaling diagram of a sixth embodiment of anetwork system according to the present invention. As shown in FIG. 32,transmission of the signaling is divided into five steps. Step 1: Aprimary base station sends a secondary serving cell addition requestmessage to a secondary base station, where the secondary serving celladdition request message includes a cell radio network temporaryidentifier of a terminal, and the secondary base station uses the cellradio network temporary identifier to scramble a random access resourceallocation message, and sends a scrambled random access resourceallocation message to the terminal; optionally, the secondary servingcell addition request message further includes activation time, and thesecondary base station determines, according to the activation time, atime for sending the random access resource allocation message. Step 2:The primary base station sends a reconfiguration message to theterminal, where the reconfiguration message includes a response windowsize and the activation time, and the terminal determines, according tothe response window size, a time window for receiving a random accessresponse message so receive the random access response message, and theterminal determines, according to the received activation time, a timefor receiving a random access resource allocation message to receive therandom access resource allocation message. Step 3: The secondary basestation sends the random access resource allocation message to theterminal, where the random access resource allocation message includes aserial number of a random access preamble code and a serial number of aPRACH mask code determined by the secondary base station. Step 4: Theterminal sends a random access request message to the secondary basestation according to the received random access resource allocationmessage, where the random access request message includes a randomaccess preamble code. Step 5: The secondary base station sends therandom access response message to the terminal according to the receivedrandom access request message, where the random access response messageincludes a time advance command TAC, so that the terminal adjusts,according to the TAC, time advance TA of the terminal on a correspondingcell. Step 2 is optional. When step 2 is skipped, the terminaldetermines, according to self-determined activation time, a time forreceiving the random access resource allocation message to receive therandom access resource allocation message, and determines, according toa default response window size, a time window for receiving the randomaccess response message to receive the random access response message.In addition, before the terminal receives the random access resourceallocation message, the terminal further receives the cell radio networktemporary identifier of the terminal sent by the primary base station,so that the terminal uses the cell radio network temporary identifier todescramble the random access resource allocation message.

According to the method for adding a secondary serving cell, theapparatus, the device, and the network system that are provided in theembodiments of the present invention, a primary base station sends asecondary serving cell addition request message to a secondary basestation, so that in a subsequent step, a terminal can correctlydescramble a random access resource allocation message received by theterminal, and correctly send a random access request message to thesecondary base station according to the random access resourceallocation message, and the secondary base station then determines,according to the random access request message, content of a randomaccess response message and a time for sending the message to theterminal. According to the embodiments of the present invention, aprimary serving cell and a secondary serving cell can still workproperly when the primary serving cell and the secondary serving cellbelong to different base stations, or a delay over a connection betweenthe primary serving cell and the secondary serving cell is relativelylong and a capacity is relatively small.

FIG. 33 is a schematic flowchart 9 of an embodiment of a method foradding a secondary serving cell according to the present invention. Themethod applies to a secondary base station, and includes the followingsteps:

Step 5301: After sending a secondary serving cell addition responsemessage to a primary base station, the secondary base station sends arandom access resource allocation message to a terminal, where thesecondary serving cell addition response message includes a cell radionetwork temporary identifier of the terminal and the random accessresource allocation message includes a serial number of a random accesspreamble code and a serial number of a physical random access channelmask code.

Specifically, after the secondary base station sends the cell radionetwork temporary identifier to the primary base station, the secondarybase station sends the serial number of the random access preamble codeand the serial number of the physical random access channel mask code tothe terminal.

Step 5302: The secondary base station receives a random access requestmessage that is sent by the terminal and carries the random accesspreamble code obtained according to the serial number of the randomaccess preamble code.

Specifically, the secondary base station receives the random accessrequest message sent by the terminal to the secondary base station.

Step 5303: The secondary base station obtains a time advance command TACaccording to the random access request message, and sends, to theterminal, a random access response message that carries the TAC, so thatthe terminal adjusts, according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

Specifically, the secondary base station determines, according to thereceived random access request message, the time advance command TACsent to the terminal, so that the terminal adjusts, according to theTAC, the time advance TA of the terminal on the corresponding cell.

Further, according to the secondary base station in the foregoing methodfor adding a secondary serving cell, the secondary serving cell additionresponse message further includes activation time, and the secondarybase station determines, according to the activation time, a time forsending the random access resource allocation message.

Specifically, the secondary serving cell addition response message sentby the secondary base station to the primary base station furtherincludes the activation time. That is, in addition to sending the cellradio network temporary identifier of the terminal to the primary basestation, the secondary base station further sends the activation time tothe primary base station, the activation time is forwarded by theprimary base station to the terminal, and the activation time is used bythe terminal to determine the time for receiving the random accessresource allocation message.

FIG. 34 is a schematic signaling diagram of a seventh embodiment of anetwork system according to the present invention. As shown in FIG. 34,transmission of the signaling is divided into five steps. Step 1: Asecondary base station sends a secondary serving cell addition responsemessage to a primary base station, where the secondary serving celladdition response message includes a cell radio network temporaryidentifier of a terminal, and the secondary base station uses the cellradio network temporary identifier to scramble a random access resourceallocation message, and sends a scrambled random access resourceallocation message to the terminal; optionally, the secondary servingcell addition response message further includes activation time. Steps2, 3, 4, and 5 are the same as steps 2, 3, 4, and 5 in the schematicsignaling diagram of the sixth embodiment, and details are not describedherein again. After the secondary base station sends the secondaryserving cell addition response message to the primary base station andbefore the terminal receives the random access resource allocationmessage, the terminal further receives the cell radio network temporaryidentifier of the terminal sent by the primary base station, and theterminal uses the cell radio network temporary identifier to descramblethe received random access resource allocation message. In thisembodiment, the cell radio network temporary identifier of the terminalis determined by the secondary base station, then sent to the primarybase station, and then sent by the primary base station to the terminal.

According to the method for adding a secondary serving cell, theapparatus, the device, and the network system that are provided in theembodiments of the present invention, a secondary base station sends asecondary serving cell addition response message to a primary basestation, so that in a subsequent step, a terminal can correctlydescramble a random access resource allocation message received by theterminal, and correctly send a random access request message to thesecondary base station according to the random access resourceallocation message, and the secondary base station then determines,according to the random access request message, content of a randomaccess response message and a time for sending the message to theterminal. According to the embodiments of the present invention, aprimary serving cell and a secondary serving cell can still workproperly when the primary serving cell and the secondary serving cellbelong to different base stations, or a delay over a connection betweenthe primary serving cell and the secondary serving cell is relativelylong and a capacity is relatively small.

FIG. 35 is a schematic structural diagram 7 of an apparatus embodimentfor adding a secondary serving cell according to the present invention.As shown in FIG. 35, a terminal includes a twenty-first unit 311A, atwenty-second unit 312A, a twenty-third unit 313A, and a twenty-fourthunit 314A. The twenty-first unit 311A is configured to receive a randomaccess resource allocation message sent by a secondary base station,where the random access resource allocation message includes a serialnumber of a random access preamble code and a serial number of aphysical random access channel mask code. The twenty-second unit 312A isconfigured to send a random access request message to a secondary basestation by using a sending resource that is determined according to theserial number of the physical random access channel mask code, where therandom access request message includes the random access preamble codethat is determined according to the serial number of the random accesspreamble code. The twenty-third unit 313A is configured to receive arandom access response message sent by the secondary base station, wherethe random access response message includes a time advance command TACthat is determined by the secondary base station according to the randomaccess request message. The twenty-fourth unit 314A is configured toadjust, according to the TAC, time advance TA of the terminal on asecondary serving cell corresponding to the secondary base station.

Further, according to the terminal in the foregoing apparatus for addinga secondary serving cell, the twenty-first unit 311A is furtherconfigured to receive a reconfiguration message sent by the primary basestation, where the reconfiguration message includes a random accessresponse window size, of the secondary serving cell, that is for theterminal to receive the random access response message, or thereconfiguration message includes the response window size and activationtime, and the terminal determines, according to the activation time, atime for receiving the random access resource allocation message.

Further, before receiving the random access resource allocation message,the twenty-first unit 311A further receives a cell radio networktemporary identifier of the terminal sent by the primary base station,and the terminal uses the cell radio network temporary identifier todescramble the received random access resource allocation message.

FIG. 36 is a schematic structural diagram 8 of an apparatus embodimentfor adding a secondary serving cell according to the present invention.As shown in FIG. 36, a secondary base station includes a twenty-fifthunit 431A, a twenty-sixth unit 432A, and a twenty-seventh unit 433A. Thetwenty-fifth unit 431A is configured to, after receiving a secondaryserving cell addition request message sent by a primary base station,send a random access resource allocation message to a terminal, wherethe secondary serving cell addition request message includes a cellradio network temporary identifier of the terminal and the random accessresource allocation message includes a serial number of a random accesspreamble code and a serial number of a physical random access channelmask code. The twenty-sixth unit 432A is configured to receive a randomaccess request message that is sent by the terminal and carries therandom access preamble code obtained according to the serial number ofthe random access preamble code. The twenty-seventh unit 433A isconfigured to obtain a time advance command TAC according to the randomaccess request message, and send, to the terminal, a random accessresponse message that carries the TAC, so that the terminal adjusts,according to the TAC, time advance TA of the terminal on a secondaryserving cell corresponding to the secondary base station.

Further, the secondary serving cell addition request message received bythe twenty-fifth unit 431A further includes activation time, and thesecondary base station determines, according to the activation time, atime for sending the random access resource allocation message.

FIG. 37 is a schematic structural diagram 9 of an apparatus embodimentfor adding a secondary serving cell according to the present invention.As shown in FIG. 37, a secondary base station includes a twenty-eighthunit 531A, a twenty-ninth unit 532A, and a thirtieth unit 533A. Thetwenty-eighth unit 531A is configured to, after sending a secondaryserving cell addition response message to a primary base station, send arandom access resource allocation message to a terminal, where thesecondary serving cell addition response message includes a cell radionetwork temporary identifier of the terminal and the random accessresource allocation message includes a serial number of a random accesspreamble code, a serial number of a physical random access channel maskcode, and the cell radio network temporary identifier of the terminal.The twenty-ninth unit 532A is configured to receive a random accessrequest message that is sent by the terminal and carries the randomaccess preamble code obtained according to the serial number of therandom access preamble code. The thirtieth unit 533A is configured toobtain a time advance command TAC according to the random access requestmessage, and send, to the terminal, a random access response messagethat carries the TAC, so that the terminal adjusts, according to theTAC, time advance TA of the terminal on a secondary serving cellcorresponding to the secondary base station.

Further, the secondary serving cell addition response message sent bythe twenty-eighth unit 531A further includes activation time, and thesecondary base station determines, according to the activation time, atime for sending the random access resource allocation message.

An embodiment of the present invention provides a terminal device. FIG.38 is a schematic structural diagram 7 of a device embodiment for addinga secondary serving cell according to the present invention. As shown inFIG. 38, the terminal device includes an eleventh receiving unit 311B, aninth sending unit 312B, a twelfth receiving unit 313B, and a thirdprocessing unit 314B. The eleventh receiving unit 311B is configured toreceive a random access resource allocation message sent by a secondarybase station, where the random access resource allocation messageincludes a serial number of a random access preamble code and a serialnumber of a physical random access channel mask code. The ninth sendingunit 312B is configured to send a random access request message to asecondary base station by using a sending resource that is determinedaccording to the serial number of the physical random access channelmask code, where the random access request message includes the randomaccess preamble code that is determined according to the serial numberof the random access preamble code. The twelfth receiving unit 313B isconfigured to receive a random access response message sent by thesecondary base station, where the random access response messageincludes a time advance command TAC that is determined by the secondarybase station according to the random access request message. The thirdprocessing unit 314B is configured to adjust, according to the TAC, timeadvance TA of the terminal on a secondary serving cell corresponding tothe secondary base station.

According to the foregoing terminal device, the eleventh receiving unit311B is further configured to receive a reconfiguration message sent bya primary base station, where the reconfiguration message includes arandom access response window size, of the secondary serving cell, thatis used by a terminal to receive the random access response message, orthe reconfiguration message includes the response window size andactivation time, and the terminal determines, according to theactivation time, a time for receiving the random access resourceallocation message.

According to the foregoing terminal device, the eleventh receiving unit311B is further configured to, before receiving the random accessresource allocation message, further receive a cell radio networktemporary identifier of the terminal sent by a primary base station,where the terminal uses the cell radio network temporary identifier todescramble the received random access resource allocation message.

FIG. 39 is a schematic structural diagram 8 of a device embodiment foradding a secondary serving cell according to the present invention. Asshown in FIG. 39, a secondary base station device includes a thirteenthreceiving unit 321B, a tenth sending unit 321 b, a fourteenth receivingunit 322B, and an eleventh sending unit 323B. The thirteenth receivingunit 321B is configured to receive a secondary serving cell additionrequest message sent by a primary base station. The tenth sending unit321B is configured to, after receiving the secondary serving celladdition request message sent by the primary base station, send a randomaccess resource allocation message to a terminal, where the secondaryserving cell addition request message includes a cell radio networktemporary identifier of the terminal and the random access resourceallocation message includes a serial number of a random access preamblecode and a serial number of a physical random access channel mask code.The fourteenth receiving unit 322B is configured to receive a randomaccess request message that is sent by the terminal and carries therandom access preamble code obtained according to the serial number ofthe random access preamble code. The eleventh sending unit 323B isconfigured to obtain a time advance command TAC according to the randomaccess request message, and send, to the terminal, a random accessresponse message that carries the TAC, so that the terminal adjusts,according to the TAC, time advance TA of the terminal on a secondaryserving cell corresponding to the secondary base station.

According to the foregoing secondary base station device, the secondaryserving cell addition request message further includes activation time,and the secondary base station determines, according to the activationtime, a time for sending the random access resource allocation message.

FIG. 40 is a schematic structural diagram 9 of a device embodiment foradding a secondary serving cell according to the present invention. Asshown in FIG. 40, a secondary base station device includes a twelfthsending unit 331B, a fifteenth receiving unit 332B, and a thirteenthsending unit 333B. The twelfth sending unit 331B is configured to, aftersending a secondary serving cell addition response message to a primarybase station, send a random access resource allocation message to aterminal, where the secondary serving cell addition response messageincludes a cell radio network temporary identifier of the terminal andthe random access resource allocation message includes a serial numberof a random access preamble code and a serial number of a physicalrandom access channel mask code. The fifteenth receiving unit 332B isconfigured to receive a random access request message that is sent bythe terminal and carries the random access preamble code obtainedaccording to the serial number of the random access preamble code. Thethirteenth sending unit 333B is configured to obtain a time advancecommand TAC according to the random access request message, and send, tothe terminal, a random access response message that carries the TAC, sothat the terminal adjusts, according to the TAC, time advance TA of theterminal on a secondary serving cell corresponding to the secondary basestation.

According to the foregoing secondary base station device, the secondaryserving cell addition response message further includes activation time,and the secondary base station determines, according to the activationtime, a time for sending the random access resource allocation message.

FIG. 41 is a schematic structural diagram 5 of an embodiment of anetwork system according to the present invention. As shown in FIG. 41,the network system includes a terminal 31A, a secondary base station33A, and a primary base station 32A. The terminal 31A receives areconfiguration message sent by the primary base station 32A, theterminal 31A receives a random access resource allocation message sentby the secondary base station 33A, and before receiving the randomaccess resource allocation message, the terminal 31A further receives acell radio network temporary identifier of the terminal sent by theprimary base station. The terminal 31A sends a random access requestmessage to the secondary base station 33A according to the receivedrandom access resource allocation message. The terminal 31A adjusts,according to a received random access response message, time advance TAof the terminal 31A on a corresponding cell. The secondary base station33A sends a secondary serving cell addition response message to theprimary base station 32A or receives a secondary serving cell additionrequest message sent by the primary base station 32A. The secondary basestation 33A sends the random access resource allocation message to theterminal 31A, and the secondary base station 33A receives the randomaccess request message sent by the terminal 31A and then sends therandom access response message to the terminal 31A according to thereceived random access request message, so that the terminal 31A adjuststhe time advance TA of the terminal 31A on the corresponding cell. Theprimary base station 32A receives the secondary serving cell additionresponse message sent by the secondary base station 33A or sends thesecondary serving cell addition request message to the secondary basestation 33A. Before the terminal receives the random access resourceallocation message, the primary base station further sends the cellradio network temporary identifier of the terminal to the terminal. Theprimary base station 32A sends the reconfiguration message to theterminal 31A.

FIG. 42 is a schematic structural diagram 6 of an embodiment of anetwork system according to the present invention. As shown in FIG. 42,the network system includes a terminal device 31B, a secondary basestation device 33B, and a primary base station device 32B. The devicesare configured to correspondingly execute the technical solution of theapparatus embodiment shown in FIG. 41. A principle and a technicaleffect thereof are similar, and details are not described herein again.

Finally, it should be noted that the foregoing embodiments are merelyintended for describing the technical solutions of the present inventionother than limiting the present invention. Although the presentinvention is described in detail with reference to the foregoingembodiments, persons of ordinary skill in the art should understand thatthey may still make modifications to the technical solutions describedin the foregoing embodiments or make equivalent replacements to sometechnical features thereof, without departing from the spirit and scopeof the technical solutions of the embodiments of the present invention.

What is claimed is:
 1. A method for adding a secondary serving cell, themethod comprising: receiving, by a terminal, a notification message sentby a primary base station, wherein the notification message comprises aserial number of a random access preamble code and a serial number of aphysical random access channel mask code; sending, by the terminal, arandom access request message to a secondary base station by using asending resource determined according to the serial number of thephysical random access channel mask code, wherein the random accessrequest message comprises the random access preamble code determinedaccording to the serial number of the random access preamble code;receiving, by the terminal, a random access response message sent by thesecondary base station, wherein the random access response messagecomprises a time advance command (TAC) determined by the secondary basestation according to the random access request message; and determining,by the terminal according to the TAC, a time advance (TA) of theterminal on a secondary serving cell corresponding to the secondary basestation.
 2. The method according to claim 1, wherein: when the secondaryserving cell is added, maintaining connection to the primary basestation.
 3. The method according to claim 1, wherein, when the secondaryserving cell is added, the method further comprises: maintaining, by theterminal, a connection to the primary base station.
 4. The methodaccording to claim 1, wherein the notification message is areconfiguration message or a random access resource allocation message.5. The method according to claim 1, wherein: the notification message isa reconfiguration message comprising a random access response windowsize of the secondary serving cell that is used by the terminal toreceive the random access response message.
 6. The method according toclaim 1, wherein when the notification message is a random accessresource allocation message, the method further comprises: receiving, bythe terminal, a reconfiguration message sent by the primary basestation, wherein the reconfiguration message comprises a random accessresponse window size of the secondary serving cell that is used by theterminal to receive the random access response message.
 7. The methodaccording to claim 1, wherein: before receiving, by a terminal, anotification message sent by a primary base station, the method furthercomprises: receiving, by the terminal, a cell radio network temporaryidentifier sent by the primary base station; and after receiving, by aterminal, a notification message sent by a primary base station, themethod further comprises: using, by the terminal, the cell radio networktemporary identifier to perform descrambling to obtain the serial numberof the random access preamble and the serial number of the physicalrandom access channel mask.